Free preview chapters
Four chapters from the full restoration guide are excerpted below — 1973-onward refreshed F-body terminal-year + SD-455 homologation overview, F-body vs A-body chassis-family distinction, bodywork & paint codes (with 1973-onward Esprit closure markers), and the engine rebuild chain.
Chapter 01
1973 seventh-year Firebird identification - 1970-onward refreshed F-body terminal year + SD-455 homologation
Lock down the 1973 seventh-year Firebird: the 1970-onward refreshed F-body 108-inch unibody terminal-year continuity (NOT the 1974-onward third-gen F-body platform rework / NOT the 1967-onward launch-year first-gen), the 1973-only Pontiac Super Duty 455 at ~310 hp homologation specialty, the 1973-onward Pontiac big-block horsepower reduction (the 1973-onward Pontiac 455 HO at 250 hp / 415 lb-ft carryover), the 1973-onward Esprit trim closure, the 1973-only ~943 Formula SD-455 cars produced, and the 1973-onward Pontiac 21 car-line prefix on the fender tag.
The 1973 seventh-year Pontiac Firebird is the FINAL year of the F-body first-generation - the 1974-onward third-gen platform rework is a separate platform. The 1973-onward continuation F-body 108-inch unibody carries the same chassis stamping pattern as the 1970-onward refreshed F-body chassis but the 1973-onward cowl tag carries a 1973-onward row encoding distinct from the 1970-onward refreshed first-year refresh / 1971-onward fifth-year / 1972-onward sixth-year cowl tag variants. Cross-reference the 1973 chassis stamping against the 1973 cowl tag row 1 / row 2 / row 5 for the 1973-onward terminal-year model year authentication.
PHS (Pontiac Historic Services) holds the 1973 Firebird documentation index by VIN - the 1973 build sheet, the 1973 invoice, the 1973 dealer delivery sheet, and the 1973 shipping manifest. A 1973 Firebird (or Formula SD-455 / Trans Am) chassis that lacks PHS paperwork has either an as-yet-undocumented car, or a chassis modified mid-build, or a chassis that lost documentation in an accident. Photograph the PHS paperwork you have: 1973 build sheet, 1973 invoice, 1973 dealer delivery, 1973 shipping manifest.
The 1973-only Pontiac Super Duty (SD) 455 at ~310 hp is the 1973-only homologation specialty terminal-year engine - a 1973-only Pontiac-side 455 cubic-inch short block casting with the 1973-only Pontiac 455 SD cylinder head (a 1973-only 455 SD-specific cylinder head casting distinct from the 1970-onward Pontiac 455 HO cylinder head, the 1970-only Pontiac 455 SD cylinder head, the 1971-only Pontiac 455 RA cylinder head, and the 1972-onward Pontiac 455 HO cylinder head at the 1972-onward 300 hp prep). The 1973-only 455 SD carries a 1973-only Pontiac-side 455 SD prefix distinct from all other Pontiac 455 prefixes.
The 1973-onward Pontiac big-block horsepower reduction is the 1973-onward primary new attractor - the 1973-onward Pontiac 455 HO at 250 hp / 415 lb-ft (a 1973-onward carryover reduction from the 1972-onward 300 hp / 415 lb-ft at the 1973-onward lower compression ratio per the 1973-onward emissions-era preparation). The 1973-onward Pontiac 455 HO carries the 1973-onward reworked cylinder head casting (a 1973-onward 455 HO reworked cylinder head for the 1973-onward cam grind and the 1973-onward lower compression ratio per the 1973-onward emissions-era preparation).
The 1973-only Formula SD-455 cars produced count - approximately 943 1973 Formula SD-455 cars were built per the 1973 Pontiac registry cross-referenced against the PHS index. The 1973-only Formula SD-455 was the most-expensive Firebird variant in 1973 (more expensive than the 1973 Trans Am because the SD-455 was a homologation-only fitment and was approximately $1,000 more than the Trans Am).
The 1973-onward emissions-era preparation also includes the cross-reference to the 1973-onward emblematic emissions-era dashboard card marker - a 1973-onward Pontiac F-body chassis carries a 1973-onward F-body dashboard card marker (a 1973-onward emblem stamping on the 1973-onward F-body dashboard) distinct from the 1972-onward sixth-year dashboard card marker.
Chapter 02
F-body vs A-body vs B-body chassis-family continuity on the 1973 Firebird
The 1973-onward F-body continues as a distinct chassis family from the 1964-onward A-body GTO / LeMans / Tempest and from the 1961-onward B-body Catalina / Bonneville. Wheelbase 108-in / 112-in / 119-in. Suspension strut-F-body / control-arm-A-body / control-arm-B-body. Body stamping unit-body-F-body / perimeter-frame-A-body / perimeter-frame-B-body.
The 1973-onward F-body (Firebird / Camaro / Trans Am), the 1964-onward A-body (GTO / LeMans / Tempest), and the 1961-onward B-body (Catalina / Bonneville) are THREE distinct GM chassis families at the 1973 model year. The 1973 F-body Firebird / Formula SD-455 / Trans Am shares no chassis stampings or body panels with the 1964-onward A-body GTO or the 1961-onward B-body Catalina / Bonneville - the 1973 F-body uses the 1970-onward refreshed F-body cowl, the 1970-onward refreshed F-body 108-inch-wheelbase chassis rails, and the 1970-onward refreshed F-body unit-body stamping.
The 1973-only Pontiac Super Duty (SD) 455 homologation specialty carries the 225 Formula SD-455 model-code prefix on the fender tag (a 1973-only triple-digit prefix distinct from the 222 base / 224 Formula / 226 Trans Am / 268 Trans Am coupe 4-speed prefixes and from the 1964-onward A-body 242 / 244 / 252 prefix). A 1973 Formula chassis claimed against the 224 Formula 455 model-code prefix reads as miscoded at the trim-level.
Reading the 1973-onward F-body Firebird model-code prefix against an A-body GTO car - the 1973 F-body Firebird fender tag carries the 222 / 224 / 225 / 226 / 268 three-digit prefix, distinct from the A-body 242 / 244 / 252 prefix. A 1973 Pontiac chassis identified by 222 / 224 / 225 / 226 / 268 model codes is a F-body Firebird; a 1973 Pontiac chassis identified by 242 / 244 / 252 model codes is a A-body GTO. (Note: the 1973-onward GTO carries 242 / 244 / 252 prefix on the A-body but is the FINAL year of the A-body GTO 1964-onward - the 1974-onward drops the A-body GTO.)
Cross-check the 1973-onward F-body stamping against the body stamping against the trim tag against the 1973 model year. The 1973-onward F-body and the 1973-onward A-body share NO body stampings at the cowl, body side, or rear-quarter - the two chassis families have different stamping patterns at every body panel. A 1973 Pontiac chassis that has F-body welded seams at the cowl AND 222 / 224 / 225 / 226 / 268 model codes is a F-body Firebird; a 1973 Pontiac chassis that has A-body rivets at the cowl AND 242 / 244 / 252 model codes is a A-body GTO. Mismatch on any of these three is a chassis that has been modified.
Document the 1973 F-body chassis-family discriminator on the trim tag BEFORE teardown. Photograph the 1973 trim tag BEFORE any fasteners come undone; the 1973 Fisher-Body trim tag on the glove-box door carries a 1973-onward Pontiac-body trim-tag pattern (a 1973-onward pattern distinct from the 1970-onward refreshed F-body trim-tag pattern, the 1971-onward fifth-year carryover trim-tag pattern, and the 1972-onward sixth-year trim-tag pattern). The 1973-onward Formula SD-455 trim tag additionally carries the 1973-only Formula SD-455-specific sub-trim designation on row 4.
Chapter 05
1973 Firebird bodywork, surface preparation, and 1973-onward emissions-era paint palette
The 1973-onward Pontiac Firebird bodywork covers rear-quarter rust repair (with the 1970-onward refreshed larger chrome phoenix rear-quarter stamping - terminal-year on the first-gen F-body), sail-panel rust repair, lower-quarter trailing edge rust, plus the 1973-onward Pontiac F-body surface prep schedule. The 1973-onward emissions-era paint palette - 1973-onward Pontiac colors with the 1973-onward emblematic emissions-era dashboard card marker.
The 1973-onward Firebird rear-quarter rust pattern is structurally identical to the 1970-onward refreshed F-body rear quarter - the rear-quarter wheel-arch lip, the trunk-to-quarter seam (a 1973-onward Fisher-Body seam), the lower-quarter trailing edge ahead of the rear bumper bracket. The 1973-onward rear-quarter stamping is the 1970-onward refreshed larger chrome phoenix rear-quarter stamping - the FINAL year of the F-body first-generation rear-quarter stamping (the 1974-onward third-gen F-body uses a 1974-onward very different rear-quarter stamping).
The 1973-onward Pontiac F-body surface-preparation schedule is the 1973-onward fourth-year refresh F-body schedule - epoxy primer as the sealer coat (a 1973-onward fourth-year refresh factory epoxy primer compatible with the 1973-onward chemistry), urethane primer-surfacer as the blocker, 180-320-400 block-sanding sequence.
The 1973-onward Pontiac F-body paint palette is stamped on the 1973 cowl tag row 4 - the 1973-onward Pontiac F-body colors include additional metallics and the 1973-onward emblematic emissions-era dashboard card marker. The 1973-onward paint palette is distinct from the 1972-onward sixth-year palette (the 1973-onward adds the 1973-onward emblematic emissions-era dashboard card marker pixel pattern).
Mask the 1973-onward Formula SD-455 / Trans Am side-script and rear-deck spoiler outline before any basecoat is sprayed. The 1973-only Formula SD-455 side-script graphic is a 1973-only homologation specialty (NOT the 1973-onward Formula standard stripe). The 1973-onward Formula SD-455 / Trans Am side-script masking is a 1973-onward carryover schedule with the 1973-only SD-455-specific additions.
The 1973-onward Pontiac F-body hood stamping is the 1973-onward shaker-style SN-60 cold-air hood stamping continued from 1970-onward on the Formula / Formula SD-455 / Trans Am trim. The 1973-onward trim closure of the Esprit means the 1973-onward Pontiac F-body has NO Esprit-only hood stamping on the 1973 lineup - the 1972-onward Esprit final-year was the LAST year of the Esprit hood stamping.
Chapter 06
1973 engine rebuild specifics - 1973-only Pontiac Super Duty (SD) 455 + 1973-onward Pontiac big-block emissions-era chain
The 1973-onward Pontiac engine chain crosses the 1973-onward Pontiac 350 / 230 OHC-6 / 400 chain on the base / Formula (without SD-455), the 1973-onward Pontiac 455 HO at 250 hp / 415 lb-ft on the Formula / Trans Am, and the 1973-only Pontiac Super Duty (SD) 455 at ~310 hp on the Formula SD-455.
The 1973-onward Pontiac 350 / 400 cubic-inch V8 engine rebuild carries over from 1972-onward with the 1973-onward cylinder head casting (a 1973-onward 350 / 400 cylinder head with the 1973-onward lowest compression ratio per the 1973-onward emissions-era preparation). The 1973-onward Pontiac 350 / 400 carries the Pontiac-side cylinder head bolt-pattern, the Pontiac-side crankshaft forging pattern, the Pontiac-side balancer pattern (4 grooves), and the Pontiac-side firing order.
The 1973-only Pontiac Super Duty (SD) 455 at ~310 hp homologation specialty engine rebuild is anchored on the 1973-only Pontiac 455 SD short block casting (a 1973-only 455 SD-specific homologation specialty short block distinct from the 1970-onward Pontiac 455 HO short block, the 1970-only Pontiac 455 SD short block, the 1971-only Pontiac 455 RA short block, and the 1972-onward Pontiac 455 HO short block). Approximately 943 1973 Formula SD-455 cars were built per the 1973 Pontiac registry cross-referenced against the PHS index.
The 1973-only Pontiac Super Duty (SD) 455 carries the 1973-only Pontiac 455 SD cylinder head (a 1973-only 455 SD-specific cylinder head with the 1973-only 455 SD-specific port pattern). The 1973-only Pontiac 455 SD cylinder head is the rarest of the 1970-onward 455 cylinder heads - approximately 943 units were built in 1973 alone; aftermarket reproductions are scarce.
The 1973-onward Pontiac 455 HO at 250 hp / 415 lb-ft engine rebuild is anchored on the 1973-onward Pontiac 455 HO short block casting (a 1973-onward Pontiac-side 455 HO prefix distinct from the Pontiac 350 / 400 prefix and from the 1973-only Pontiac 455 SD prefix). The 1973-onward Pontiac 455 HO carries the 1973-onward Pontiac 455 HO cylinder head casting (a 1973-onward 455 HO reworked cylinder head with the 1973-onward cam grind and the 1973-onward lowest compression ratio per the 1973-onward emissions-era preparation).
The 1973-onward Pontiac engine rebuild chain pairs the 1973-only Pontiac Super Duty (SD) 455 / 1973-onward Pontiac 455 HO with the 1973-onward Turbo-Hydramatic TH350 three-speed automatic (a 1973-onward carryover) or the 1973-onward Turbo-Hydramatic TH400 three-speed automatic (a 1973-onward Pontiac big-block TH400 - TH400 is a 1973-onward Pontiac big-block fitment) or the 1973-onward Muncie four-speed manual (a 1973-onward Muncie M20 / M21 / M22). The 1973-only Formula SD-455 fours-speed is paired with the Muncie M22 rock-crusher gear set.
