Along with being cheaper to build, this allowed more consistent valve action with less weight than a conventional shaft. The overhead-cam six-cylinder engine was new for 1966 and the standard engine in the Tempest and Tempest Custom. Kits for Pontiac applications. Like previous generations of Ram Airs, it used Pontiac's special cast-iron "headers". Valves: Competition Products stainless steel, 1.92 /1.66-in It was renamed 428 HO for 1968. 1966 Pontiac Catalina 2-Door Sedan full range specs - Automobile-Catalog Exhaust: 180 cfm at 0.500-in The 1971 455 HO was rated at 335hp (250kW) @ 4,800rpm and 480lbft (651Nm) of torque @ 3,200rpm (gross). Based on the same short-deck as the 301, the "LS5" 265.1cuin (4.3L) was offered only in 1980 and 1981. Size cfm: Total flow, 1,050 cfm Diameter: 516-in Low-performance and two-barrel applications, the standard engine in full-sized Pontiacs, got 1.96in (49.8mm) intake and 1.66in (42.2mm) exhaust valves and pressed in rocker arm studs. Head mods: Port, cook, magnaflux, glass bead, convert to screw-in studs The 400 2-barrel kept the 17 degree valve angles for '67; starting in '68 all Pontiac V8s went to the 14 degree valve angle. It shared the 389's 3+34in (95.3mm) stroke, but its bore was 3.78in (96.0mm) for a displacement of 336.66cuin (5.5L). The first of the "big journal" Pontiac V8s, it had a bore and stroke of 4+332in 4in (104.0mm 101.6mm) and came with dual four-barrel carburetors. 068) to 301/313 (No. The cylinder heads on the 400 CID version had an intake port volume of 290cc (17.70cuin), nearly twice the size of a typical standard D-port Pontiac head - and flowed in the area of 315cuft/min (8.9m3/min) @ 0.8in (20mm) valve lift; in the realm of the NASCAR-dominating Chrysler 426 Hemi. pontiac timing ???????? | The H.A.M.B. Muscle cars wouldn't have much muscle without horsepower -- but what exactly is horsepower? From 1977 to 1981 there were 4 distinct 301 versions: For 1981 model year vehicles, the engine codes are the 8th digit of the VIN. A History Lesson in Pontiac V8 Power - Engine Builder Magazine NASCAR race cars embody the muscle car philosophy of power. Some 400s were dealer installed. The 2+2 option package arrived for 1965, giving the Catalina a performance persona and credentials to match. This was underrated at 330hp (246kW). However, the engine used in these Trans Ams was the same regular production 455 taken from the big body cars Pontiac was producing, and output 200 HP with a torque rating of 330lbft at 2,000 rpm.[13]. High output Pontiac V8 Cylinder Heads. Tri-Power equipped Pontiac hot roda stout piece by anyone's standards. A set of Hooker Super Comp headers will be used on the dyno, and Jim is porting the stock heads to increase intake-port flow by 30 cfm. engine, dual exhausts, three-speed manual transmission, Hurst shifter, 3.42:1 rear gears, heavy-duty suspension, bucket seats, upgraded upholstery, carpet, emblems, "Decor" louvers, pinstripes, lower . Unfortunately, that's what happened with the 1963 Pontiac Super Duty 421. The most famous S/D of them all. 1962 Pontiac Catalina 421 Super Duty Royal Bobcat - Collector Car Ads Mods: Flow-test indicated '66 center carburetor would be required to improve total cfm, adapter made to fit '66 center carburetorIGNITION 1965 Pontiac Grand Prix with a 421 Tri-Power engine - YouTube The main upgrade for the engine was the ESC, (Electronic Spark Control)[15] which provided slightly more power at 170hp (127kW) with 4.9L (299cuin) for the 19801981 model years. 744) and a new valve spring package with dampers to positively control valve action. Its cast "670" heads had taller valve spring heights than the standard D-port heads, and the only 14-degree valve angle closed combustion chamber making these heads unique. . The Fresh Air package continued into the 1966 model year. . 1966 yk 421 376 a 3x2 1967 zg 230 165 a 1 1967 zm 230 165 a 1 1967 zk 230 165 3 m 1 1967 zs 230 165 3 m 1 . Modified versions of this engine were extensively used in NASCAR stock car racing and drag racing competition. Along with proper parts selection, accurate machining and assembly are also important Year: CU IN: Casting # 1967: 326. Reductions in reciprocating weight free up horsepower. 1966 Engine Codes ; Code: Application: Displacement: Compression: Horsepower: Transmission: Heads: Camshaft: Carb: WA : 389: 8.6:1: 256: Manual: 91: 254: 2 bbl: WB . Bore and stroke were 4.121in 2.84in (104.7mm 72.1mm) 303.63cuin (4,976cc). Optional engines included the 356hp Tri-Power as seen on our feature car (code WH manual or YJ auto), or the 421HO, rated at 376hp . Pontiac RAIII/IV Engine parts collection Price $14000.00. 1966 Pontiac Complete 389 Engine YC code 290 HP Block Catalina . Chamber: Closed, special to PMD, 70 cc However, a few dealers would offer them in the GTO or Firebird and do their own installations, such as Royal Pontiac who offered the "Bobcat" conversion. designs, the SD-455 was a much improved engine. 1969 - 400 Ram Air III Code 62. 1964, 1965, 1966, 1967 Pontiac Catalina 2+2 | HowStuffWorks Only one is known to survive today. This S/D retains the original "Traction Master" traction bars and two-bar spinners on the original 8 . Once corrected the SD-455 was recertified and was released for production in late April 1973. The goal of making a Pontiac Hemi succeeded but the engine was never produced. Paul Stenquist. Brand: Fel-Pro head and intake/ SCE pan and timing cover The Pontiac 389 engine was produced from 1959 to 1966, and has a 4.06" bore and 3.75" stroke. The earlier 1975-78 blocks had metal shaved from the journals and bottom end as well as a decrease in the nickel content of the block in an attempt to decrease the overall weight of the vehicle to help alleviate emissions and cost. This camshaft sported a 308-/320-degree duration with 0.47-inch (12mm) lift. 1966 Pontiac Ventura Specifications. In 1970 the casting number #9799914 Ram Air 400 4-bolt main block also used the 4-bolt main caps on Ram Air applications. The code consists of 3 or 4 digits. For a few more ponies through better oil control, a factory full-length windage tray will be added, since Pontiac didn't use one on this engine originally. The single four barrel was rated at 333 bhp while the Tri-Power version carried a 348 bhp rating. Simply called "Ram Air" by Pontiac[17] it was the first in a series of engines available from Pontiac as regular production line options and officially called Ram Air. That's the factory rating of the legendary 421 H.O. 1969 - 400 Ram Air III or 350HO Code 48. Block casting # 9773157. During 19511952, Pontiac had 23 287cuin (4.7L) V8-equipped 1953 model production prototypes running tests on the GM proving grounds. Horsepower: See Part 2 Update your shipping location. The 1955-up Pontiac V8 that finally reached the public was an overhead valve engine with cast iron cylinder heads and block and wedge-shaped combustion chambers. The engine was dubbed the TEMPEST V-8, a nickname it retained until the end of 1960. It was rated at 360hp @4300 RPM in the GTO and 370 @ 4600 RPM in the Grand Prix and other full-size Pontiacs. The 1966 Pontiac Ventura doesn't necessarily come up when speaking of 60's muscle cars, but the type of V-8's offered with the Ventura meant plenty of power. RamAir 4 Motor Price $15500.00. Math, not gasoline, makes horsepower under the hood of a Pontiac. like the earlier 1971-1972 motor, but it was not the same motor, and featured standard d-port heads with a very conservative camshaft. The block is still at standard 421 bore size (4.09375") and will be bored to fit standard size forged 428 pistons (4.120"). or choose Generic to see kits that might fit a . Total Timing: 36-deg BTDC 1962 - 389 SD Code 544127. It was factory rated at 366hp at 5,400 RPM and 445lbs.ft. The 303 had shorter connecting rods, smaller 2.5in (64mm) journals and a solid lifter version of the Ram Air IV camshaft. For the first time, Pontiac offered Tri-Power, three two-barrel carburetors with a sequential linkage (replacing the previous dual-quad set-up). For 1956 the V8 was bored out to 3.9375in (100.01mm), increasing displacement to 316.6cuin (5.2L). There were a few 1962 Grand Prix models that came with a 421 SD from the factory so if someone is lucky enough to have one today then they have a car that is probably worth some decent money simply because of the rarity of these models.if(typeof ez_ad_units != 'undefined'){ez_ad_units.push([[580,400],'enginefacts_com-medrectangle-3','ezslot_2',115,'0','0'])};__ez_fad_position('div-gpt-ad-enginefacts_com-medrectangle-3-0'); Engine Facts 2023. Specs datasheet with technical data and performance data plus an analysis of the direct market competition of Pontiac Catalina Vista 421HO Trophy V-8 Tri-Power 4-speed in 1964 the model with 4-door hardtop sedan body and V-8 6902 cm3 / 421.2 cui, 276 kW / 375 PS / 370 hp (max) offered since October 1963 for North America U.S. special version. Given that, it was no accident that the leader in intermediate muscle also put together the finest full-size performance machine -- the 1966 Pontiac 2+2. The valve size increased as well, to 2.11in (53.6mm) intake and 1.77in (45.0mm) exhaust valves on high-performance heads. Well, gaze upon these numbersa 421ci Pontiac with Tri-Power carburetion. He wanted to confirm his parts are up to the task of holding the cylinder pressure that creates horsepower. 18 watchers Pontiac V8 engine - Wikipedia The fuel-injected engine became an option on any Pontiac model, carrying a staggering price tag of $500 (almost 15% of the car's base price). Jim told HPP, "Since I was a young man in the '60s, I always thought how great it would be to find a true 100hp in a legendary 421 Tri-Power setup that retained its iron heads and intake. For 1967 only Pontiac called this engine the Quadra-Power 428. Power output ranged from 135hp (101kW) to 170hp (127kW). The "670" head was a 1967-only casting, and the only PMD head to have a closed chamber with the new 14 degree valve angle. This resulted in a lightweight design weighing less than the Chevrolet small-block V-8. More 400cuin (6.6L) engines were produced by Pontiac than the other versions - estimates range from 80 to 200 units. Block/Crank combo: '64 four-bolt 421 / '64 OE 4.00-in stroke See profiles, photos, and specifications of, Muscle cars came in many shapes and sizes. Model Number: Body/Style Number: Body Type & Seating: Factory Price: . The W72 was only available for a very short time, with the majority of 1979 model year W72 Firebirds ordered in late 1978. Are you thinking of buying a 2007 muscle car, or any other car? Rear Main Cap. This is the original car featured in the May 1962 issue of Motor Trend Magazine that was modified by Royal Pontiac and driven by Jim Wangers. There was also the addition of dual exhaust, and for vehicles equipped with a manual transmission, a slightly more aggressive camshaft. Pontiac V8 Cylinder Heads - Casting numbers and Specs - WOW Muscle Cars In 1969, Pontiac unveiled its Trans Am model Firebird, and since racing rules required engines of less than 5L (305.1cuin), Pontiac unveiled the 303 for racing models only, never available to the public. It also sports the four-speed manual, limited . Rods: Howard's billet 4340 certified steel, stock 6.625-in, floating pins Windage tray: Original PMD '70 455, fabricate fit, no bosses at cap #2 Splayed main caps, head bolts tie into main caps. The Ram Air IV heads had 1/8" taller intake ports, larger intake port volume with more airflow, yet shared the Ram Air II round exhaust ports. 1966 Pontiac GTO. Make way for one of the baddest muscle cars of all time, the, An all-aluminum, race-proven V-8 defined the rare and wicked, The engine is what gives a muscle car its flamboyant personality. PONTIAC : 1965-75Tune-up Specifications : Year: Engine Car Model: Spark Plug Type (AC) - Gap: Point Gap: Dwell Angle: . 1966 Pontiac Catalina - Oldride Pontiac V8 Engine Tune Up and Torque Specifications - WOW Muscle Cars 301 2-barrel (135hp, 101kW), (5th character of the, 301 4-barrel (150hp, 112kW), (5th character of the. Vacuum advance: Not usedEXHAUST Standard motor was the 421 4 barrel with 342 horsepower, which was no slouch itself. This simply meant that Pontiac installed both the SD-389 and SD-421 into vehicles on its assembly line. Preparation: File-fit for end gap if needed, wash Original plans called for a forged crankshaft, although actual production SD455s received nodular-iron crankshafts with minor enhancements. Pontiac planned to produce the 1953 models with the V8, but Buick and Oldsmobile appealed to GM management and earned a 2-year delay. Open pressure: 282 pounds at 1.100-in With some WS6 "Trans Am Special Performance Package" bundles in 1978, the W72 engine was incorporated with the WS6 option group and not listed on the dealer order invoice. A camshaft with 301/313 degrees of advertised duration, 0.407-inch (10.3mm) net valve lift, and 76 degrees of valve overlap was specified for actual production engines in lieu of the significantly more aggressive Ram Air IV-spec camshaft that had originally been planned for the engine (initially rated at 310hp (231kW) with that cam), but ultimately proved incapable of meeting the tightening emissions standards of the era with sufficient margin to satisfy Pontiac emission engineers given expected volume production variations. It was removed from the design for the 1960 model year because designers moved the generator and the power steering pump from atop the front of the engine down to the front of the heads to accommodate a lower hoodline. . Pontiac still offered the regular 455 (RPO L75) in its full sized cars, and after a negative public reaction for dropping the 455 engine, it was re-introduced mid-year as an available option for the 1975 Pontiac Trans Am. superior_queens (3,035) 100%. In 1969, Pontiac also used a revised crankshaft out of a Pearlitic malleable-iron, although it still used the "N" casting letter. [4] It was replaced by the 455 for the 1970 model year. The first letter equals the month. 4/21: Not just a date, but a legendary 421-cid Pontiac engine that 1967 - 400 Ram Air or 428 Code 670. Boost was wastegate limited to 91psi (0.6210.069bar). The 421 SD became factory installed in 1962 and in 1963 a street version became available from the factory with a dual four-barrel or three two-barrel Tri-Power carburetion. All 1980 Trans Ams received this engine as standard with the option to delete this engine choice as a credit option for the standard L37 301. Pushrods: LPC chrome moly However, in the June 1974 issue of SUPER STOCK AND DRAG ILLUSTRATED, a new 1974 Trans Am with the SD-455 motor ran 14.25 @ 101mph (163km/h). [19], Parts for Ram Air V engines are not readily available. The SD-455 used round-port cylinder heads similar to those used on the 1971 and 1972 455 HO, with specific "LS-2" intake and cast-iron exhaust header manifolds. Pontiac's SCCA Trans-Am program was promising, with race-ready engines producing 475hp (354kW) to 525hp (391kW), however the series General Competition Rules required the manufacturer to produce no less than 250 vehicles with the 303. Collector size: 3.00-inGASKETS In 1967, Pontiac moved on to a technologically simpler nodular cast iron (invented in late 1940s) crankshaft, which they used until 1975. Fuel pump: Will use 110-gph Carter One of the key upgrades were the 6x4 heads. Learn how Classified Ads works . - P.B. . It tips the scales at 3,950lbs. The four-barrel version, set up for sustained high speeds, had 390 hp. 1966 Pontiac Catalina - conceptcarz.com Simply put, what good is the power if the engine does not last? The standard head seen on an L78 400 Pontiac was the low compression 6x8 head, while the 6x4 head seen on the W72 had hardened valve seats for a higher RPM operating range, improved air flow, and higher compression. [20] Pontiac asked Mopar (Chrysler, Dodge, Plymouth) for help in designing it and making it work. The 421 badging was standard on the 2+2, the 421 H.O. While all this sounds great, remember the engine will have to retain the small 1.92-inch intake valve because chamber space is too tight for larger ones. Pontiac's 428 was a sneak attack in the muscle car horsepower wars 301 Turbo (210hp, 157kW), (with the 5th VIN character being a "T". ENGINE. Pontiac V8 Cylinder Heads - Wallace Racing The W72 Performance Package also included an upgrade to the rear differential ratio, setting the rear gear ratio to 3.23 for all 1977 and 1979 W72 Firebirds, with the exception being 3.42 for 4-speed equipped W72 Firebirds in 1978 only. Preparation: Magnaflux, check for equal stroke and index, grind, polish 0.010-in This new material had stronger alloys in the iron. Ellingson Motorcars (877) 638-7170. According to the engineers who worked on the project, the SOHC 421 engines produced around 625hp and were capable of turning 7,000 rpm. This was to ensure there was enough fuel to cool the cast offset dished pistons. gasoline (petrol) engine with displacement: 6902 cm3 / 421.2 cui, advertised power: 252 kW / 338 hp / 343 PS ( SAE gross . They came up with a 269-cubic-inch (4.4L) L-head design. These same heads were also used on the 1964 GTO 389 tri-power engines. The Block Date Code represents the production date of the engine. Balancer: Original PMD rebuilt by Damper Doctor Pontiac Engine Torque Specs - Butler Performance Super Duty 421s were back, tougher than ever. The 455 HO package was only available to late model year Pontiac Firebird Trans Am's, and was mandatory with a 4-speed transmission. With A/C On, Engine Hot: 421: 1966: With Tri-Carb, With Air Injection reactor: 45S: 0.035: To determine horsepower from airflow, invert the equation: Pontiac 421 Tribute to the legendary muscle car engine Price $15500.00. Valve seals: U.S. Seal The last "true" Pontiac V8s, a 265 and 301cuin (4.3 and 4.9L), ended production in early 1981. In basic 2-barrel form it produced 290 horsepower and 428ft. pounds of torque in 1968. 1968 - 400 Ram Air II Round Port Code 96. The short deck engine weighed about 40lb (18kg) less than the other variants and had an 8000 rpm redline. It was rated at 310hp (231kW) @ 4800rpm and 400lbft (542Nm) @ 3,000rpm on 10.5:1 compression. Lift: 0.515/0.525 with 1.6:1 rockers The tri-power equipped XS-code 389 was shipped with the Ram Air pan in the trunk, and the dealer had to fit it and cut out the underside of the hood scoop to make it functional. [8] All of these improvements provided the W72 with a power rating of 200hp (203PS; 149kW) at 3600 rpm and 325lbft (441Nm) of torque at 2400 rpm, while the standard L78 400 only produced 180hp (182PS; 134kW) at 3600 rpm and 325lbft (441Nm) of torque at 1600 rpm. It was rated at 475hp (354kW). Oil pump: . True Pontiac engines were designed and built in Detroitnot on a computer, but often by GI-bill-educated engineers who grew up working with their hands and now had a slide rule in their pocket instead of a greasy rag. Free shipping on many items | Browse your favorite brands | affordable prices. Retainers: Crower steel So large are the intake ports that the pushrods run through the center of each port via pressed-in tubes, in addition to streamlined airfoils over the tubes themselves to improve port shape, and increase flow velocity. Installed position: 110-deg This had extra-rich "DX" secondary metering rods and a remote vacuum source for the primary metering rod enrichment circuit to allow the Power Enrichment Vacuum Regulator (PEVR) to release the primary metering rods to move to the up position (enrichment) anytime during boosted conditions. 1966 Pontiac 2+2 $64,995. 1966 Pontiac GTO - Muscle Car Facts It's well documented that an internal combustion engine is nothing more than an air pump. . The Pontiac 2+2 featured a 6.9 L V8 engine, heavy-duty front springs, dual exhaust and distinctive exterior body design. This was a project started with the end goal of building a 427 Hemi. A panel covers the dash opening where the radio would have been on a standard Catalina. The 301.6cuin (4.9L) 301 was offered from 1977 to 1981 and also installed in other GM cars during those years. Now select an engine model (if applicable) -- Pontiac Engine Models -- All Pontiac Kits 151 301 326 350 3800 389 4-cylinder 400 421 428 455 Brodix Heads Edelbrock Heads Iron Duke L67 Pro Stock Dart Heads Pro Stock Heads Ram Air Runner Heads Super Duty Generic V8. In 1961 and 1962 they were available with either one 4 barrel carburetor or a dual 4 barrel carburetor setup depending on whether the buyer wanted to head to the racetrack or drag strip. Idel RPM Automatic In Drive Notes; 326: 1964: 45S: 0.035: . The shaker wore the decals "455 H.O." V-8 (coded WG for stick or YH for auto) was the 2+2's base engine. Nevertheless, there appears in the October 72 issue of MOTOR TREND, a road test of a 1973 SD-455 Grand Am. Engine Oil: 120 ft-lbs. Next time we will cover the induction system and the dyno testing to see if Jim meets his goal. SPECIFICATIONS. "1966 Pontiac 2+2" However, the 1959 389 engines had the generator in front of the heads with reverse flow cooling still in use. The 389 was the standard engine on the GTO up to 1966. After the 1974 SD455 was dropped the 1975 Firebird's top performance engine was an 'L78' Pontiac 400cuin (6.6L). CO2, . Engine Year Info Spark Plug Plug Gap Point Gap Dwell Angle Timing (BTDC) Idel RPM Manual Tran. The 455 was used through 1976 when it, as with many other large displacement engines, was discontinued as manufacturers moved to smaller, more efficient models, even in their full size car lines. Two different cylinder-head castings were used for the 1962 model year, both with a combustion chamber volume of 68cc (4.15cuin) to produce an 11.0:1 compression ratio. To learn everything you need to know about car engines, see. Bearings: Sealed-Power mains and rods, cam Dura-Bond As Pontiac still wanted to offer a performance motor to compete in the performance market, they looked back to the 400 Pontiac and how it could be improved to offer greater performance while meeting CAFE standards. Engine, horsepower, torque, dimensions and mechanical details for the 1966 Pontiac Catalina. Lobe separation angle: 112-deg The 455 HO designation made its debut in 1970; Rated at 360 or 370hp (268 or 276kW) (depending on which vehicle it was installed into) & 500lbft (678Nm) of torque, it differed from the regular full sized car 455 by large valve heads with smaller combustion chambers, and a larger camshaft. PDF Pontiac Engine Decoder The 1971 455 HO was available in the Firebird (optional in Formula; standard in Trans Am), the GTO (standard with "The Judge" package), and the 2-door LeMans, LeMans T-37 (including GT-37), and LeMans Sport. The 1971 Pontiac 455 HO was Pontiac's first engine to receive a special 800cuft/min (23m3/min) Rochester Quadra-jet carburetor with specific jetting. We and our partners use cookies to Store and/or access information on a device. In 1973 a further refined and even stronger but less powerful version, the Super Duty (SD) engine, was planned for Firebird, Grand Am, Le Mans (GTO), and Grand Prix models. Here is another number to ponder: 370 hp. Rings: LPC (Liberty Performance Components) premium moly, standard tension Bore/Stroke ratio: 1.04:1 (imp.) Offered from 1967 to 1969, it produced 360 and 376hp (268 and 280kW) in 1967, 375 and 390hp (280 and 291kW) in 1968 and 360,370 and 390hp (268,276 and 291kW) in 1969. Specifications listing with the performance factory . It remained on the same platform, but for the 1966 models, it became a different Pontiac series. Distributor: '61 Delco cast-iron with direct oiling The heads were a new design featuring siamesed intake ports. For '65, the 421-cid V-8 became a standard part of the option package, and for '66, Pontiac made the 2+2 a separate model, still based on the Catalina two-door hardtop or convertible. 3.75. Dual Carter Carburetor 500cuft/min (14m3/min) #3433S (front) and #3435S (rear) carburetors with manual chokes and mechanical linkage. Continue with Recommended Cookies. Building a rare Pontiac Catalina Royal Bobcat piece by piece Likewise, the top 428 carried the same 376-hp rating as the 1966 Pontiac 421 Tri-Power motor. The 1975 455 HO package received some negative press/reviews as some buyers expected to see a return of the 1971-1972 engine, and were disappointed when they received the lower output motor. The short-deck block and different intake ports also required the design of a new intake manifold. Head bolts do not pull on the cylinder wall causing distortion. In 1964 when the new "A" body intermediates came out there was a new corporate (GM) engine size limitation to anything less than 330cuin (5.4L). Pontiac Heads - Butler Performance Two-barrel carburetor, 8.5:1 compression, 227hp (169kW) @ 4600rpm, 333lbft (451Nm) @ 2300rpm, Four-barrel carburetor, 10:1 compression, 244hp (182kW) @ 4800rpm, 350lbft (475Nm) @ 2600rpm, Two-barrel carburetor, 10.0:1 compression, 244hp (182kW) @ 4800rpm, 350lbft (475Nm) @ 2600rpm, Four-barrel carburetor, 10.25:1 compression, 270hp (201kW) @ 4800rpm, 359lbft (487Nm) @ 2900rpm. 5 January 2007. In light of this, the 'Year' entry, as indicated by the chart below, may actually represent the year that the heads were cast, versus the year that they were actually installed on an automobile. However, the RA II was limited to a 1.50:1 rocker ratio, while the RA IV used a 1.65:1 ratio, which yielded significantly greater total lift and, therefore, superior flow and power. moniker from the shaker due to the disappointing public approval as the motor was not deemed to be "High Output". Lot S152 1962 Pontiac Super Duty 421 405 HP 4 Speed - YouTube The 455 HO moniker was again carried over, this time as a near-exact repeat of the 1971 offering, the only changes were the carburetors (they used a conventional 750cuft/min (21m3/min) unit this year), and the head castings (casting #7F6). Whether all were installed in GTOs is unknown. 1975 Factory Service Manual lists the SD-455, but the SD-455 did not meet emissions for the 1975 model year and was canceled. Pontiac 389 Engine Guide - Muscle Car Club Pontiac in the 1950s was one of a few US manufacturers that did not regularly identify their engine names and sizes with air-cleaner or valve-cover decals. #9770716 aka "716" heads featured a 170cc intake port volume, and were considered a milder "street" version of the vaunted SD421 Super Duty heads. For 1974 another 1,001 (943 Trans Am, 58 Formula) were built, after which the SD-455 was discontinued. Other dimensional factors such as the wheel base, curb weight and length were largely unchanged. Effectively, Pontiac's V8s were all small blocks, sharing the same connecting rod length 6.625 in (168.3mm) (except for the later short deck 301 and 265 produced in the late 1970s and early 1980s before Pontiac adopted universal GM engines). The mighty Pontiac 421 was a star on the drag strip and a super nova on the Nascar tracks of the first half of the 60s. In 1963 Pontiac dropped the Buick division built 215 cu. For '65, the 421-cid V-8 became a standard part of the option package, and for '66, Pontiac made the 2+2 a separate model, still based on the Catalina two-door hardtop or convertible.Flamboyantly styled and expansively proportioned, the 2+2 was unbeatable for sheer presence. The concept car Pontiac Strato-Streak was used to introduce the V8 and in later years the engine was installed in Pontiac products. Regarding Crower's upgrade suggestions for its camshaft, Jim pretty much has it covered. First offered as an option in 1963, the 421 HO came in a 4-barrel engine of 320hp (239kW) and one Tri-Power H-O version with a hotter cam and efficient iron exhaust manifolds and rated at 370hp (276kW). The 421 SD Tri . The last was the 421 HO and included a high-output camshaft and valve train. In 1969 the 350 HO was upgraded again with the addition of the 400 HO cam, commonly referred to by enthusiasts as the 068 cam.