Driven Restorations: 1973 Pontiac 400 Built for HP and Fun!

Years of storage and memories on the road have this 1973 Pontiac Grand Am showing it's age with a moldy and mouse infested interior and worn out smog motor. It pulled into the shop running on 7 cylinders with a plume of blue smoke behind it. This wasn't quite what the owner remembered enjoying about the car when he first got it in the mid 70's.

It was quickly decided that a complete mechanical overhaul was a necessity. With orders to add a lot more power, enhance handling and freshen the interior, we began tear down on this customer project in the summer of 2015. It's going to be a sleeper, keeping the original look and paint of the classic Pontiac. The Hooker Aerochamber mufflers and new Crager wheels are the only hints at what's hiding under the hood.

BEFORE: 1973 Pontiac 400 smog motor, stock

BEFORE: 1973 Pontiac Grand Am: broken front facia

The seats have seen better days. Mice and mold are eating the upholstery away bit by bit. All new interior is on the way!

Let the work begin!

Engine is removed and mechanical dis-assembly is under way

Pontiac 400 removed from the Grand Am

Disassembly in progress, headed out for machine work

The Pontiac 400 is finished with machine work and ready for assembly and paint

Pontiac 400 ready for assembly and paint

The Pontiac block gets a fresh coat of paint

Assembly of the Pontiac 400 including aluminum heads

Assembly nearing completion

Pontiac 400, fully re-built and ready for dyno testing

Dyno day set up

Tuning and warm up on dyno day at Advanced Engine Concepts

The owner of the car is happy with his results!

See the final "hard pull" on the dyno

The re-built Pontiac 400 now makes 475 HP and 515 ftlbs torque!

The re-built Pontiac 400 is installed into the re-painted engine bay after being broken in and hitting awesome test numbers on the dyno!

This Grand Am engine and engine bay smelled more like a mouse nest than anything close to a car

AFTER: The '73 Grand Am engine bay with fully rebuilt Pontiac 400, A/C upgraded to efficient pump, electric fan, headers, Demon carb and many new mechanical features