// 1993–2002 PONTIAC FIREBIRD / TRANS AM — LT1 & LS1

F-Body Parts Verdict

Straight answers on which parts you can buy aftermarket, and which ones will come back to bite you — built specifically for LT1 (1993–97) and LS1 (1998–2002) Firebirds and Trans Ams, including known TSBs and recalls for this platform.

27
Parts Covered
LT1 / LS1
Both Engines
4
TSBs & Recalls
All Parts
OEM Required
Aftermarket OK (caveat)
Aftermarket OK
27 parts TAP A PART TO EXPAND
// DOCUMENTED BY GM & NHTSA

Recalls & Service Bulletins

These are real, verifiable bulletins pulled from GM service documentation and NHTSA records — not owner-forum guesses. TSBs are informational (not safety recalls) except where noted. Coverage windows have shifted across revisions, so always cross-check your specific VIN and model year.

// FULL BULB CHART

Light Bulb Reference

Every exterior and interior bulb position for 1993–2002 Firebird & Trans Am, plus the headlight housing swap people ask about most.

VERIFIED SWAP
The "LMC Truck" Headlight Swap
Stock 1998–2002 headlights are H4701 (high beam) / H4703 (low beam) sealed beams — the same physical sealed-beam housing size GM used on 1988–91 C/K trucks, Blazers, and Suburbans. Because of that shared housing size, the composite headlight housings LMC Truck sells for those old trucks are a direct physical fit into the Firebird's headlight buckets — no cutting or grinding of the bucket itself.
The catch: LMC's truck housings are built for 9005 (high beam) / 9006 (low beam) bulb connectors, not the Firebird's factory H4701/H4703 connector. So it's a direct housing fit, not a true plug-and-play — you'll need to either splice in the new connector or run a 9005/9006 adapter pigtail.
Buy straight-connector bulbs, not right-angle. F-body owners who've done this swap report that right-angle 9005/9006 bulb connectors require trimming the headlight bucket to clear. Straight-connector versions fit without any bucket modification.
// SERVICE SPECS

Fluid Capacities & Types

LT1 and LS1 differ enough on capacities that mixing up the numbers is an easy mistake — kept separate here on purpose.

// TRIMS & PACKAGES

Model & Trim Guide

What separates a Formula from a Trans Am, what WS6 actually is (hint: not a model), and how to verify a Firehawk or special edition is real.

// WHAT CHANGED WHEN

Year-by-Year Changes

The running changes that actually matter for identifying and working on these cars.

// BEFORE YOU BUY

Used F-Body Buyer's Checklist

Points worth checking before handing over money, whether it's for you or you're helping a group member look at one.

// COMMON DTCs

Diagnostic Codes, Plain English

The codes that come up most on this platform, paired with the parts above where relevant.

// ELECTRICAL GREMLINS

Common Ground Point Locations

Before chasing an electrical gremlin through wiring diagrams, check these — corroded or loose grounds cause a disproportionate share of "weird" electrical problems on these cars. These are enthusiast-documented locations, not an official factory diagram, so treat them as a starting checklist rather than the complete list for your exact car.

// GLOVEBOX LABEL DECODER

RPO Code Glossary

Quick reference for the option codes printed on your service parts label (glovebox on 1993–97 cars, driver's door jamb on later cars). Handy for verifying what you actually have.

// BOLT PATTERN & SIZING

Wheel & Tire Fitment

Every 4th gen Firebird/Trans Am shares the same bolt pattern — what changes is wheel width and offset by trim.

Going Wider Than Stock
A common street setup without major fender work: 17x9–9.5" front (50–56mm offset), 17x10–11" rear (45–50mm offset). A 315/35-17 rear tire matches the diameter of the factory Z-rated 245/50-16 option, so no speedometer recalibration is needed. Going wider than an 11" rear wheel typically requires rolling or hammering the inner fender lip, trimming the jounce bumper bracket, and recentering the axle with an adjustable panhard rod.
// COMMON QUESTIONS

Before You Ask