Autoblog and Yahoo may earn commission from links in this article.Don't let the Trans Am badge fool you – this Arizona-based 1977 Firebird is a long way from stock. It's been treated to a 6.2-liter LS3 V8 crate engine, a Tremec T56 Magnum six-speed, four-wheel disc brakes, modern A/C, digital gauges, and a fresh coat of black paint. The odometer? Just 1,400 miles since the overhaul.1977 Pontiac Firebird Trans AmBring a TrailerWhat It's Worth Right NowIf you're wondering what these cars are worth, Classic.com pegs the second-gen Trans Am Special Editions (1976-1981) at $69,543. The market's seen 47 sales, averaging $75,382, with prices swinging from a bargain-bin $7,100 all the way up to a jaw-dropping $265,000. The latest sale? $76,500.AdvertisementAdvertisementBut before you get too excited, keep in mind those numbers are for original or near-original Trans Am Special Editions. This Firebird is a different animal – heavily modified and not playing in the same league. Right now, you'll find a 1977 listed at $179,900 and a 1978 manual at $139,995, just to show how much collectors will pay for untouched examples. Another 1977 manual? Listed at $174,947.1977 Pontiac Firebird Trans AmBring a TrailerFor this build, I'd ballpark fair value somewhere between $30,000 and $45,000. That takes into account the modern drivetrain, the quality of the upgrades, and the fact that it's not an original survivor. That's my estimate, not Classic.com's. With the current bid at $20,300 and a few days left, there's still room to move – just make sure it's a real factory Trans Am before you throw your hat in the ring.Condition and DetailsYou still get that unmistakable second-gen Firebird silhouette – shaker hood, Firebird graphics, front and rear spoilers, dual mirrors, and 17-inch Snowflake-style wheels with gold accents. It used to be yellow, but now it's black. The seller points out a crack in the windshield and some exterior blemishes, so don't expect a concours queen here.1977 Pontiac Firebird Trans AmBring a TrailerUnder the hood, things get serious. The 6.2-liter LS3 crate engine went in back in 2020, courtesy of Arizona High Test. It's got an aluminum intake, beefy long-tube headers, Holley front accessory drive, Be Cool radiator, dual electric fans, and custom mounts. Power heads to the rear via a Tremec T56 Magnum six-speed. Brakes? Stainless lines, cross-drilled and slotted rotors, Wilwood master cylinder, adjustable proportioning valve, and Wilwood calipers – six-piston up front.1977 Pontiac Firebird Trans AmBring a TrailerInside, you'll find black vinyl seats, Vintage Air heat and A/C, power windows, a center console, and a JVC CD stereo with Bluetooth. The Dakota Digital dash packs a 160-mph speedo, 8,000-rpm tach, and all the usual gauges. The digital odometer reads 1,400 miles since the build. Service records and an Arizona title are included.1977 Pontiac Firebird Trans AmBring a TrailerAdvertisementAdvertisementThe OfferSpecificationDetailMakePontiacModelFirebird Trans AmYear1977Mileage1,400 miles shown since completion of buildEngine6.2-liter LS3 V8 crate engineTransmissionTremec T56 Magnum six-speed manualDrive typeRear-wheel driveExterior colorBlack, repaintedInterior colorBlack vinylWheels17-inch Snowflake-styleBrakesWilwood four-wheel disc setupLocationMesa, ArizonaInterested in this car? View the listing here.What Makes the Firebird UniqueThe appeal here comes from the combination of a familiar late-1970s Firebird body and a much newer powertrain. Instead of retaining a period Pontiac engine, the build uses a 6.2-liter LS3 crate V8 paired with a T56 Magnum six-speed, giving the car a modern drivetrain while retaining the long-hood, short-deck proportions and shaker-hood appearance associated with the Firebird. The addition of Wilwood brakes, upgraded cooling, long-tube headers, and modern air conditioning also makes the build more usable than a strictly stock example.1977 Pontiac Firebird Trans AmBring a TrailerOne thing to watch out for: a commenter on the auction says the VIN points to this being a Formula, not a real Trans Am. That's just a heads-up from the peanut gallery, not a confirmed fact, so check the VIN and original paperwork before you call it an authentic Trans Am.Final ThoughtsBottom line: see this as a modified second-gen Firebird, not a rival to those pristine, original Trans Ams on Classic.com. The LS3, T56, Wilwood brakes, better cooling, modern A/C, and digital gauges make it a totally different beast from a stock '77. The low 1,400 miles since the build is a nice bonus.AdvertisementAdvertisementThe current $20,300 bid leaves room for the auction to move considerably. I would pay particular attention to the VIN question, documentation for the conversion, the quality of the LS3 installation, the repaint, and the noted windshield damage before deciding how high to bid. If those checks come back favorably, the car could make sense for someone who wants the look of a classic Firebird with a substantially more modern drivetrain.Disclaimer: This post is for informational purposes only. We are not a dealership or broker. All vehicle specifications, pricing, and availability are subject to change without notice. We are not responsible for typographical errors, omissions, or the accuracy of the provided information. Please verify all details directly with the seller.Autoblog aims to feature only the best products and services. If you buy something via one of our links, we may earn a commission.This story was originally published by Autoblog on Aug 19, 2026, where it first appeared in the Car Buying section. 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