The screaming eagle on the hood and shaker scoop are the Trans Am's calling cards. These Motown icons are being restored in record numbers.
Year to Year Changes: On the surface, Firebirds look similar from 1970 to 1981. The truth is there were a lot of changes to drive trains, sheet metal and interiors. A 1976 Trans Am doesn't even share the same shell as a 1974. The 1970 Trans Am features the endura nose with two large grilles and a shaker hood. It was available only in Polar White or Lucerne Blue with contrasting stripes. The 1971 Trans Am is almost identical except for new bucket seats with integral head rests and the all new 455 HO engine. 1972 featured Trans Ams with different honeycomb patterned grilles; otherwise they were similar in appearance to the 1971. More cars started to appear with honeycomb mag wheels which became optional in 1971.
1973 was the first year for the full size Trans Am hood decal. It was optional and some cars did not have it. Color choices expanded to include Buccaneer Red and Brewster Green with Cameo White. Lucerne Blue was dropped. For 1974, Trans Am had new vertical finned grilles and the chrome rear bumper was gone, converted to body color molded endura like the front. Color choices expanded to include Admiralty Blue. The large hood bird decal grew in popularity and the small nose cone decal was changed to an emblem.
By 1974, Pontiac Trans Ams were available in new colors including Admiralty Blue.
1975 was the first year for the wrap around rear window. The grilles were changed to horizontal fins with integral turn signals. You could get Trans Ams in many colors by now. 1976 featured a new front end with blacked out grilles and turn signals under the bumper. 1976 was the first year for what became known as the Special Edition package. It was a black Trans Am with gold pin stripe accents and gold hood bird. Marketed that year as a 50th Anniversary model, it returned in 1977 as a top of the line Special Edition Trans Am.
1977 introduced a new front end featuring curved grilles similar to a 1959 Pontiac but with new modular headlamps. The 1978 model is virtually identical in appearance. 1979 was the biggest change in appearance for the Trans Am with a new front and rear end design. The grille virtually disappeared, shrinking to small vents with the turn signal lenses. The rear end gained a massive tail lamp assembly that lit up across the back when brakes were applied. The fender spoilers grew larger as well. The hood decals were the largest and most colorful of the series. In 1980 the only notable appearance change was a new hood with a bulge for the turbo 4.9 Trans Am engine option. It included a unique decal.The Trans Am stayed the same to the end of 1981 in appearance. A 1981 can be identified by the use of a firebird emblem on the gas tank lid.
The 1977-78 Trans Ams look alike except for small details.
By 1979, the grilles went under the bumper while decals and spoilers grew immense.
Drive trains and popular options: In 1970, the Trans Am engine was a 400 cubic inch V8 available as a Ram Air III with Ram Air IV optional. For 1971, the Ram Air engines disappeared and were replaced with a 455 High Output (HO) version. The Trans Am engine for 1972 was also a 455 HO. They were available with four speed or automatic transmissions. New for 1973 was a 455 Super Duty engine which included round port heads, aluminum manifold and special exhaust manifolds, high lift camshaft and four bolt main blocks with webbing. The SD455 was optional and the base 455 was standard. The SD455 option was available in 1974 in limited quantities. The other engines available were the base 455 and the 400, which returned as an option for the first time since 1970.
For 1975 the only engines available were the 400 and 455. The 455 was extremely limited as the option was dropped as engineering changes to the transmission cross member and new catalytic converters were being implemented. In 1976, the 455 returned for the last time as the premier option while the 400 was the base mill. For 1977, engine choices ranged from a new W72 high performance 400, a base 400 and an Oldsmobile 403 V8 available in California only that year. From 1978 to 1979 only two engines were available nationwide; the 400 Pontiac and the Oldsmobile 403. In 1980 the engines were limited to a 4.9 liter four barrel Pontiac and a turbocharged 4.9 option. In 1981, the Pontiac V8 ended production, necessitating a switch to the Chevrolet 305 V8 about half way through the year.
The 455 is the most favored engine followed by the W72 400.
By March 1981, only the Chevrolet 305 V8 was available.
Popular options include power windows, air conditioning, tinted glass, honeycomb wheels on '71-76 cars, forged aluminum wheels on '77-'81 cars and hatch roof panels from '77-'81. Technically the hatch roof panels were available in 1976 but only on the 50th Anniversary Trans Am. The favored engines in order of desirability are the 455 HO, the standard 455, the W72 Trans Am 400 and a tie between the Oldsmobile 403 and the base 400. The last performance engine was the turbo 4.9 V8 from 1980-81
What to Look For: When buying a Trans Am, ninety percent of your time is spent looking over the unibody. These cars are major rust buckets. Here is a list of the weak areas you have to check with every year Trans Am. The rear axle kick up and rear frame rails, the rocker panels including the door sills, trunk lid and floor, lower quarter panels, rear fender spats, front fender spats, tops of front fenders. The hood hinge, supporting sheet metal and cowl area joining the dash to windshield are notorious rust areas.
It's common to replace lower rear fenders due to rust. Patch repairs panels have been made for years, but you still have to find donor pieces if you're replacing an entire rear quarter panel. Trunk lids often rust from the inside out and what is visible is just a small portion of the cancer. You're wise to replace the entire lid.
Rear fender patch repairs are very common due to trapped dirt under the fender spats.
The hood hinge, supporting sheet metal and cowl area joining the dash to windshield are notorious rust areas .In addition, the windshield pillars at the base of the metal dash are notorious for rusting. Many amateur repairs with filler have been done which only makes it worse as metal filler holds moisture. If the car has holes in the corner of the dash larger than most coins, I would pass on it. On a car with hatch panels, this can be a real problem. Shown is a picture of the entire area to be checked thoroughly especially on a T roof car.
Condensation cycles can rust panels from inside out. It's cheaper to replace with new metal than repair this trunk lid.
Use a business card to check for rust between the fender spats and sheet metal. If you pull it out and rust stains or debris shows up, you could have repair work. Remove the sill plates and check the rocker panels. Usually, you'll find rust at the bottom where the rear fender meets the sill. Likewise, rust out occurs where the sill meets the front fender above the fender bolts. The engine sub frame is a bit weak on the pre 1976 models, so rust out can be a problem. The '77 and later sub frames are better but all of them suffer from rusted cage nuts and bolts, making bushing replacement a big job in a complete restoration.
The entire hood hinge and metal cowl area into the windshield pillars are notorious for rust. Check it carefully on hatch roof cars.
When it comes to restoring these cars, the reproduction parts supply is very good. You'll need to rely on donor cars for new roofs, full rear quarter panels and certain one year only pieces. As with any classic car, parts chasing is only part of the expense. Bodywork, paint and assembly are what consume all the money. While Special Edition Trans Ams and certain desirable models such as the 455 HO are worth restoring properly, a basket case car missing its drive line or with substantial rust should be passed over unless you don't mind doing the work yourself or writing the checks for someone else to do it. They made a lot of these cars, so be picky and find one that is in good shape.
Verification & Documentation: Pontiac fans are lucky when it comes to verifying their car's authenticity. It isn't that hard to do. The ideal find is a car with the original engine, transmission, rear axle, body and interior in good shape. Not many of these cars exist in that condition. These cars were hot rodded over the past 30 years, so a matching numbers drive train is a worthwhile plus. All the Trans Ams have a partial VIN number stamped on the engine block between the lower water pump hose and by pass outlets. The 1980-81turbo 4.9 engines have the serial numbers engraved in script style at the bottom of the block. A two letter suffix code stamped on the passenger side below the cylinder head indicates what type of engine is in your car. For a Chevrolet 305, the machined pad on the passenger side of block under the cylinder head contains the same info including the partial VIN. The Oldsmobile 403 engine has a partial VIN stamped in the same area but under the driver side cylinder head.
Look for engine code and VIN on the front in the water pump outlet hose area.
The casting date stamp is found next to the distributor hole on Pontiacs and Chevrolets with a two digit year followed by a letter- digit combination indicating month and date of manufacture.
The automatic transmission has a two letter code silkscreened on a metal plate attached to the modulator body with a production date stamped below it. The VIN number is stamped on the oil pan rail on the driver side of a TH400. You may have to use a hoist to see it on dual exhaust equipped cars. With the manual Borg Warner ST-10 transmissions, the partial VIN is stamped on the top of the gear case on a raised pad. On older 1970s era T-10s, the VIN can appear on the driver's side of the gear case near the date code. I've seen them stamped both ways. Sometimes the VIN appears alongside the date stamp beside the aluminum midplate joining the tail shaft to the gear case. The early seventies Trans Ams used Muncie gear boxes and the VIN stamp is found on a raised boss on the right forward side of the case near the production date.
Some Trans Ams you'll pay a premium for including Special Editions, 455 HO cars and tenth Anniversary Editions. Fortunately, the SE cars from Norwood, Ohio, usually have a code on the cowl tag indicating that option. Look for Y82 on 1977 to 1979 model and Y84 for 1980-1981 models. A gold Special Edition was made for about 9 months and it was coded Y88. The Tenth Anniversary Trans Am had its own VIN code, look for X87 in the VIN number. Sadly, with the value of SE cars rising, a number of replicas and fakes are being produced. It isn't that hard to do with cowl tags and VINs for sale on major websites.
It makes sense to protect yourself with a high dollar purchase such as a Super Duty 455, a 455HO, SE Trans Am or Pace Car by having the VIN number checked with PHS Online service. Pontiac Historical Services provides a sales invoice copy of the car with a list of options and selling dealer when the car was new. It will determine for sure whether that black and gold Trans Am is really an SE or just a replica. Jim Mattison has the files of Pontiac muscle cars produced and he worked for GM when the program was handled in house. When Pontiac decided to outsource this valuable function, Mattison negotiated the acquisition. It's money well worth spending to assure what you're buying. These tips will help you pick a high flying bird from a dodo.