1973 Pontiac Firebird restomod: 455 EFI, Tremec TKX five-speed, C5 brakes, finished in 2024

Why we picked it

This 1973 Firebird started life as an Esprit with a 350 and was rotisserie-restored and rebuilt by Ray Maruska of Duluth, Minnesota, finishing in 2024. It now runs a Pontiac 455 with aluminum heads, aluminum intake and Holley Sniper EFI, ceramic-coated headers into a stainless exhaust, and a Tremec TKX five-speed in front of a rebuilt 10-bolt with a new limited-slip and 3.73 gears. CPP tubular control arms with coilovers, Hotchkis rear leaf springs, C5 Corvette four-wheel discs and 18-inch Weld wheels handle the chassis side. Vintage Air and custom black and gray leather finish the inside. The body has 1970 Trans Am-style front-end parts, a shaker hood, flush-mounted glass, shaved side markers and a narrowed, tucked rear bumper in Ford Antimatter Blue. Clean Minnesota title.

This isn't a 20%-under bargain at the asking price: modified and custom 1973 Firebirds have been selling for about $55,000 to $57,000. We're listing it because the build quality and parts list are well above those comps, and the parts and labor would be hard to match for the money. It just finished a Hemmings auction without meeting reserve at $44,500 and is now open to offers. The seller says the reserve was reasonably set, so there may be room to negotiate.

The value check

When we found it, the seller was asking $56,700. Comparable cars in the same condition have sold for $55,000–$57,200, so the middle of the market is about $56,100.

Modified and custom 1973 Firebirds sold for $55,000 to $57,200 in June-September 2026 (Barrett-Jackson twice, Bring a Trailer). At $56,700 this is priced at the market; its no-sale auction topped out at a $44,500 bid, about 20% under.

Where the numbers come from:

• 1973 Firebird Formula, modified, BaT, $56,500 (Sep 2026)
• classic.com 1973 Firebird market (Barrett-Jackson results)

What to check

• Ask for build records and receipts, and a dyno sheet if one exists; the seller estimates 400-450+ hp but it has not been dynoed
• The original 350 is gone, so this is a builder's car, not a numbers car
• Check the quality of the custom bodywork closely: flush glass, tucked bumper and narrowed panels are hard to repair if damaged
• Confirm the Sniper EFI tune is sorted for hot and cold starts
• Hemmings charges a 5% buyer's fee on top of the price
• Arrange an in-person inspection in Duluth before making an offer

Making it drive like new

The hard work is done. Remaining upgrades would be personal: a power rack-and-pinion conversion, three-point belts, and sound deadening if it is going to be a long-distance car.

7 builders make a complete chassis for the 1970–81 Second-gen Camaro & Firebird. Compare them side by side, along with what it takes to stiffen the factory frame.

How it ended

It sold for $52,500 on Oct 5, 2026, against a market value of about $56,100 when we found it.