71 GP Questions.
 

I just bought a 71 GP parts car. I'm not that familiar with GP's. I have a couple questions? The PO claims the car was originally a 455 car. There is no engine or trans with the car.

Did the 455 cars come with a 12 bolt rear end? What ratio?

Is the steering gear different between a GP and GTO? The dealer brochure lists the GP as 2.9 turns lock to lock, while the GTO is 3.5 turns. Or is the steering geometry different?

The front seats in the car look more like a Firebird seat than a GP seat, But the seat material matches the rear seat. I thought the seats were more like the GTO seats with a headrest.

Thanks for you input.

J or SJ? I'm pretty sure 12 bolt & 3.07 gear standard for 455. Steering box don't know thought they were the same! Those are newer seats not 71'.........73 & up maybe 76 or 77 not sure.

Thanks

The car is a J

I did some research on O'Reilly's and Autozone's website, and the GP and GTO use the same Pitman Arm, Idler Arm, and Steering Gear. So why do the specs say 2.9 turns on the GP and 3.5 on the GTO? Whats different?

Ames shows different part numbers for the idler arm.

J the 455 had to be ordered. 400 was standard engine. Kinda rare to find one like that today.
Build sheet usually behind pass door panel & lower back seat.

Thanks, I'll look for it when i get a chance

I checked a couple of GP's and A bodies. The GP's both have a 2.9 lock to lock steering box. My 70 GTO with a 70 GP steering box is 2.9. I checked a 71 and 72 Lemans Sport and they are both 3.5 lock to lock.

mrrat1, I checked for the build sheet but it's no longer there. Looks like the interior was previously removed, sure it disappeared at that time.

Did factory 455 GPs have the unique, larger motor mounts and plates on the frame like A-bodies?

71 had "Strato buckets", those seats in yours are out of maybe a Camaro or Firebird. Good news is Strato Buckets came in A-bodies and Grand Prixs from 69 thru 72.