Updates since 07 Sep 2000 are in red. Updates since 20 Mar 2001 are in purple. Updates since 01 Aug 2006 are in blue-green.
Can t find it here? Look in the h-body.org forums. Frequently Asked Questions about these car models from 1971 to 1980: Chevrolet Vega and Pontiac Astre Chevrolet Monza, Buick Skyhawk, Oldsmobile Starfire, and Pontiac Sunbird Maintainer: Dennis Brown Contributors and Sources: GM H-Body Owners Association HBOA Yahoo Group A list of people who sent me information or were quoted from the message board is here. h-body.org Forums members Standard Catalog of American Cars 1946-1975, John A Gunnel editor, Krause Publications, Iola, WI, 1987. Standard Catalog of American Cars 1976-1986, James M Flammang editor, Krause Publications, Iola, WI, 1988. Chilton s Repair & Tune-Up Guide: GM Subcompact 1971-80, Martin J Gunther editor, Chilton Book Company, Radnor, PA, 1983.
Building the V8 Chevy Monza by Bob Gumm Website H-Special Registry Website Marco s Monza World (was Monzabudd s 1975-1980 Chevy Monza Web Site) Robert Spinello (vegabob) Varlop s 1980 Chevy Monza Project Website Some of the links above may be dead, but they remain to give credit. HEY! You too can contribute! If you see something that s wrong or missing (look for ???
) and have the correct info, let me know! NOTE: Some information in this FAQ was gathered from the above sources. This information is not copied verbatim, and where such information is not considered common knowledge, permission was granted to use the information here (specific cases will be noted). Thus to my knowledge no copyright violations have occured. Please still visit the sites listed above! They have much more info that is NOT listed here!
Disclaimer: This information is provided free to the reader. It may used for any purpose, however, the maintainers and contributors take no responsibility for injury to yourself or damage to your belongings as a result of your reading this document and following its advice. Names: In this document, in most places, Vega can be understood to mean Vega or Astre, and Monza can be read as Monza, Sunbird, Starfire, or Skyhawk. Chevrolet, Buick, Pontiac, Oldsmobile, Vega, Monza, Sunbird, Starfire, and Skyhawk are all names owned by General Motors Corporation. H-Body FAQ Contributors The following club members have written posts on the HBOA Yahoo!
Club message board or e-mailed me information that I have included in the FAQ. I have listed only their first names and Yahoo IDs--see Yahoo profile for more information, if they have to provided any. The numbers indicate the number of times I ve included a direct quote from that person. AJ ( sbc77vega) Al ( alfred_howe) 3+lots of magazine articles Aleck ( stinkybuttihave) 5 Bob ( botizan) 2 Bob ( venom_symbiot) Bill ( vegasmb383) Bill ( bill504a) Bill ( bhrinc) ( birdman8099) Brian ( Bacchus_101573) 2 Brian Harpst ( ???) Britt ( kiva75) 4 Brew ( mongoose_brew) 4 ( Chvyfan1) Cliff ( dracer327) Clyde ( CJBIAGI) 12 Craig ( michman11) Dan ( vegon71) Dan ( dancv32) Dave ( cuzworth) Dave ( vegatex) 3 David ( monzaaddict) 3 Denis ( calgary_spyder) Denis ( denisst78) 12 Dick ( monza75tc) Don ( mrdonjeffers) 2 Duke ( doctorduke) 8 Eric ( erdowell) Erik ( erik_norway) George ( VEGAGT76) Ian ( ian_mccrimmon) ( jay27_85304) Jeff ( monzafan) 2 John ( Lord_Varon) John B ( vegadad) 16 Jon ( jon72vega) Ken ( mahoy78spyder) 15 Ken ( kckken) Keith ( mr_phelcher) Kevin ( SoloII_74) 9 Kirk ( kcdragmonza) Larry ( vega_man_larry) 9 Lenny ( lenny1_70) Marco ( Monzabudd) 3 Mike ( mich_southpaw) Mike ( monzter_327) Myles ( mylesgt) 3 Nick ( nickster1_99) 3 ( panel73) Paul ( pvgatto) 3 Phill ( DRAGMONZA) Randy ( monzamiler) 3 Rob ( MonzaRob) Robert ( twelve_second_vega) 15 Roger ( ks_skyhawk) 3 Roger ( monza_madness) 2 Ron ( vega355) Sean ( spkorb) Tim ( TimMcCabe99) 4 Tim ( cosworth_twincams) Todd ( tallen_77346) Tom ( tbecker_525) Tom ( TheAstre) 3 Tom ( tjvanoverbeke) 2 Tony ( Tonyhallo) 3 Tony ( tony63underwood) Wade ( wade78spyder) These members posts are quoted with credit given with only changes to fix typographical errors.
If a member wants me to alter or remove his/her information, please see the contact page. The H-Body Organization FAQ Table of Contents -- Monza, Vega, Astre, Sunbird, Starfire, Skylark Contents Introduction Contributor List General Information Stock Engines Transmissions and Rearends Rear Axle Identification Steering and Suspension Wheels, Tires, and Brakes Exterior/Chassis Interior and Safety Electrical System Engine Swaps Transmission Swaps Groups, Clubs, Organizations, Websites Vendors Click here to get the whole FAQ as one HTML document. H-Body FAQ Section 1 1 General Information 1.1 What is the GM H-body, basically? 1.2 What are the different H-body models?
1.3 What are the special or rare factory H-bodies? 1.4 What are some aftermarket special H-bodies? 1.5 What changes were made to the Chevrolet Vega for each model year? 1.6 What changes were made to the Pontiac Astre for each model year? 1.7 What changes were made to the Chevrolet Monza for each model year? 1.8 What changes were made to the Buick Skyhawk for each model year?
1.9 What changes were made to the Oldsmobile Starfire for each model year? 1.10 What changes were made to the Pontiac Sunbird for each model year? 1.11 How many of each model was produced? 1.12 What s this I hear about a rotary engine in the Monza? 1.13 What s up with the 1999 Chevrolet Monza and reincarnations? 1.14 How do I decode the VIN on my H-body?
1.15 How do I decode the trim tag on my H-body? 1.16 What are some Vega/Astre option codes? 1.17 What are some Monza/Sunbird/Starfire/Skyhawk option codes?
1.18 What s a restoration pack? 1.19 Where can I find magazine articles about the H-bodies? 1.20 What are some H-body books? 1.21 What are some H-body models? 1.22 What movies have H-bodies in them?
1.23 What TV shows have H-bodies in them? 1.24 How fast are stock H-bodies? 1.25 Where can I buy H-body stuff? 1.26 Are there 1974 or 1981 Monzas? 1.27 How can I insure my restored H-Body? 1.28 What Monzas came with white letter tires?
1.29 What is the Vert-a-pact option (VK5)? 1.1 What is the GM H-body, basically? The H-body was GM s subcompact car for the seventies, sold in six different models: Chevrolet Vega and Monza, Pontiac Astre and Sunbird, Buick Skyhawk, and Oldsmobile Starfire. Each model has a 4, 6, or 8-cylinder engine in the front and a solid rear axle to move the car.
All bodies are of unit-body construction (no separate frame). All styles have four seats, two doors, and are available in notchback, hatchback, or wagon forms (depending on brand). There are economy- and performace-tuned models.
The line was replaced in the early eighties by the transverse front-engined front wheel drive GM J-Body (Chevrolet Cavalier, Pontiac Sunbird, etc.). ??? The H-Bodies were developed by GM Lead Engineer Ed Cole, who also developed the Corvair and Fiero. The Vega was designed with a Chevy Small Block V8 in mind, but the Corvette group protested enough to kill that option. H is the internal code GM used to identify the car platform. For example, some other codes are F for the Camaro and Firebird, P for the Fiero, Y for the Corvette, G for the RWD Monte Carlo and Grand Prix, and so on.
Letter codes change and get reused. Most recently, H was used for the large FWD platform used by the Pontiac Bonneville and Buick LeSabre. 1.2 What are the different H-body models?
There are two major variations of the H-body, one based on the Chevrolet Vega and one based on the Chevrolet Monza. Vega sales began in 1971. The Pontiac Astre, almost a clone of the Vega except for minor cosmetic changes, was sold in Canada, then introduced to the US in 1975. The Vega was sold in hatchback, notchback, wagon, and panel wagon versions.
All Vegas were sold with 1bbl or 2bbl 2.3L four cylinder aluminum-block OHC engines, except the DOHC Cosworth Vega sold in 1975 and 1976. The Vega 2300 won Motor Trend s Car of the Year for 1971. Vega sales ended with the 1977 model year.
The Monza was introduced in 1975. GM s other brands also introduced their versions of the Monza: the Oldsmobile Starfire, the Buick Skyhawk, and the Pontiac Sunbird. The Monza, based on concept cars designed by Pininfarina (1971/1972 Ferrari GTC+4), was designed to use a two rotor Wankel engine, but that engine never reached production. Instead, the Monza appeared with either the Vega s 4-cylinder or a 262ci small block V8 (350ci in California).
Later engines include the Pontiac Iron Duke 2.5l inline four, a 3.2l V6, the Buick 3.8l V6, and the Chevy 305 V8. The Monza 2+2 hatch won Motor Trend s Car of the Year for 1975. All H-body production ended for the 1980 model year. 1.3 What are the special or rare factory H-bodies?
Astre Formula Al (Astreformula) writes: After seeing the pictures of the Astre Formula on George s (VegaGT76) website, I stumbled across such a car. It took me 3 months of convincing to acquire the car. What information I obtained about the car came from 2 sources: 1977 sales brochure and the Standard Catalog of American Cars 1976-1986 book. The Formula option was only offered in 1977 for the Astre. It was also the only year that Pontiac offered the 2.5L motor. The Formula option would get you special decals, handling package, chrome valve cover, Formula TA steering wheel and a 3 piece rear spoiler.
Out of the 12,120 HB s built, there are no production numbers for the Formula option. Astre SJ See Vega GT. Cosworth Vega The centerpiece of the Cosworth Vega is the Cosworth-designed Dual Overhead Cam 16 valve engine. Based on the 2.3l block in the other Vegas, the DOHC engine is 2.0l and uses Bendix electronic fuel injection controlled by a Motorola computer. The engine has an aluminum block and head and uses a stainless steel exhaust header and HEI ignition. The engines were built in Tonawanda NY and installed in Vega bodies produced off the regular assembly line in the Lordstown OH plant.
The engine produces 120hp @ 5200RPM (an experimental engine using an 11.5:1 compression ratio produced 270hp @ 8750RPM!). In addition to the engine, Cosworth Vegas received a heavy-duty front suspension, the torque-arm rear suspension introduced in the Monza, miscellaneous interior enhancements, and a Twin Cam nameplate on the instrument panel engraved with the car s number. 2061 were built in 1975 and 1446 were built in 1976. The price was around $6000. Millionth Vega Robert Spinello (vegabob) contributed: In May 1973, Chevrolet produced the one millionth Vega. A million buiilt in three years!
Chevrolet chose a GT Hatchback coupe featuring a bright orange exterior with white sport stripes, a neutral custom vinyl interior featuring exclusive vinyl door panels, orange accent color carpeting, power steering and Millionth Vega door handle accents. Chevrolet produced a special limited edition Millonth Vega replicating the milestone car. 6500 were built at the rate of 10 cars per hour from May through July 1973.(10% of total production for 3 months) Millionth Vega - ZM5 option $497.00 included: GT Package Power Steering Bright Orange Exterior (code 86) White Sport Stripes Light Neutral Custom Vinyl Interior w/exclusive Vinyl Door Panels Accent-Color Carpeting - Orange Millionth Vega Door Handle Accents Hot Rod magazine, in December 1973 said: .They ll probably sell a million of em.
Notes: Regular production options were available not in conflict with the ZM5 package - (any transmission, a/c, etc.) Bright Orange Exterior color was offered as a regular production Vega color (code 69) in 1974 (only). Vinyl Door Panels became part of the Custom Interior option from 1974 on. By 1973, total Vega production was up to over 100 cars per hour at the Lordstown, Ohio Assembly Plant - it was by far, the fastest auto production rate in the world. Still, a GM of Canada plant was also utilised to keep up with the demand in 1973-74. Monza Cabriolet (same options as Vega Cabriolet) Monza California 350 Brian Melka (Bacchus_101573) writes: The California Monza was alive for the 1975 and 1976 years.
The 1975 cars had anemic 125hp 350 2-barrel engines and only came with automatic transmissions (more on that in a minute). The 1976 cars had a 305 2-barrel engine. The 350 was only offered in 1975 California Monzas and the 305 that was offered in 1976 was only offered in California Monzas. The 305 became an option on all-states cars in 1977. There are still a handful of these cars left. All of the cars that are currently documented are notchbacks.
There was a special option K-code car as well. This 1975 California Monza included a 350 4-barrel engine. There are currently only two known to exist. One is owned by Tony Underwood in Ohio and the other is in Southern California. The car located in Southern California is a demo car only. Tony s car is especially rare in that it had 4-speed (rumored to not be available on California cars) and an Astro roof and no Air Conditioning (rare on a California car).
Only two Monzas are documented to have had the Astro roof conversion. It is rumored that Tony s car was a special order executive or dealer car that was not available to the general public. It is likely one of the rarest publicly-held Monzas in existence. Sean (spkorb) says GM told him 3400 5.7l Monzas were built.
Don (mrdonjeffers) adds: Confirmation of the number 3400 75 350 Monza s. I too called GM, but back in 1982. I was switched around to mutiple numbers of people until finally someone was able to verify the correct numbers. His exact words were there were 3366 5.7litre Monza s made and given vin tags/paper work. I would venture to say that given the cars rarity and the fact that many people hacked on, or hot rodded so many of these cars that there are probably only a few hundred correct, stock ones out there.
Monza Mirage The Monza Mirage wears body cladding that resembles the Monzas racing in the IMSA Camel GT series, only toned down for the street. This includes a front wraparound air dam, wider front fenders, wider rear fenders, a matching wraparound rear spoiler, badges, and stripes. The package was only available on hatchback Monzas (without the Spyder package) with any engine, but the V8 was recommended. When the package was first made available in 1977, white was the only exterior color offered. For the 1978 model year, these colors were to be offered: Code 13 Silver with Firethorn Stripes Code 19 Black with Gold Stripes Code 75 Light Red with Gold Stripes but production ended with the 1977 model year.
The package was designed by BORT, Inc. of Grand Rapids, Michigan, for Michigan Automotive Techniques Corporation. The Mirage could be ordered from any Chevrolet dealer; the car would then be built on the regular assembly line and drop-shipped to Michigan Automotive Techniques Corp., who would add the Mirage options and ship the car to the dealer where the order was placed. The MSRP of the option package was under $700. Ken Mahoy supplied this info from the M.A.T. order form: It is recommended (but not mandatory) to maximize the distinctive visual appearance and ride characteristics of the package and car that the following options be ordered: D35 - Sport Mirrors QKZ - BR70-13/C White Lettered Radial Tires U14 - Special Instrumentation N31 - Sport Steering Wheel F41 - Sport Suspension LG3 - 5.0 Litre 2-bbl.
V-8 Engine CAUTION: The following Chevrolet options are not compatible and must not be ordered: B84 - Body Side Moldings B93 - Door Edge Guards B96 - Wheel Opening Moldings Z01 - Spyder Equipment Package Z02 - Spyder Appearance Package. Monza Sport This package includes a black-out treatment for the B pillar, a front stabilizer bar, and high-back bucket seats. Monza Spyder Available on hatchback and notchback body styles in 1976, this package includes special Spyder body decals, 2bbl 2.3l engine, floor console, F41 suspension package, special instrumentation and instrument panel, BR70 or BR78 tires, and the five-speed manual or three-speed automatic transmission (this is the Z01 RPO).
In 1977 the package added Rally II wheels, front and rear spoilers, and black accents on headlamps, taillamps, and many other pieces that are chrome on non-Spyder cars (Z02 RPO). Note that Z01 and Z02 could be ordered independently. Monza Super Spyder II (aka Stiletto) Ken Mahoy provides this information: Prototype Monza 2+2 that was orginally developed by Jerry Palmer at the GM Design Center as a lighting concept , with a Corvette-looking front nose, rounded-off one-piece rear tail section with a fixed rear spoiler, reminiscent of the GTO Judge, and louvered taillights (like the 66 GTO).
GM lighting engineers developed a long fluorescent tube buried in the car s nose behind a plexiglass shield that provided low-beam illumination for urban night driving, while twin high-powered Cibie driving lights were faired into the under-side of the nose for high-speed travel. Powertrain was the 16-valve Cosworth engine, except with twin (45mm) Weber carbs, and a Borg Warner 5-speed coupled with a 4.10 rear axle. It was painted a unique palomino, platinum gold color. The hood had nice visual effects, such as extensive pinstriping and clearance blisters which were intentionally asymmetrical to simulate an aircraft fuselage. One blister was a functional passenger-side air intake, and the driver s side blister housed a digital speedometer! Under the flaired fenders resided FR60-14 Goodrich Radial T/A s on German BBS lightweight racing wheels (14X7 front, 14X8 rear).
Visually, it was one of the most pleasing Monza prototypes ever built. Monza.