suspension part interchangeability?

[59chev]

Were there any major changes in the front suspensions on Pontiac Grand Prix's from 78-81? I had heard that parts could interchange throughout these years. Springs, shocks, A-arms, sway bar, steering box ect.

Also is there any difference in the motor mounts for a Pontiac engine vs a Chevy small block?

Thanks

 

[thebaron]

I used a heavy duty gearbox out of early montey for my 84 GP and SS Coil springs for my front suspension (sits up a bit high until the 350 swap 😉

 

[clean8485]

If memory serves me correctly, the front wheel bearing sizes were different on the 1978 A body models, as compared to the '79-'81 models, which means that the '78 front spindles are also different. Also, in 1980 or '81, GM changed the style of flare on the ends of the power steering pressure lines from a double flare style to the later O-ring style. Another thing-I believe in 1982, GM changed the wheel stud threads from SAE to metric. As far as I know, those are the only changes that I can think of. Other than that, suspension parts should be interchangeable from 1978 to
1988. If I've missed anything, hopefully one of the other members here will pick up on that. Hope this helps.

 

[SV6 REGAL]

Here some more info http://www.bowtiepower.com/Gbody_chassis.html

 

[85 Cutlass Brougham]

I believe the mounts will be different between the Pontiac and Chevy engines. There are numerous mounting holes in the front crossmember for the different engines that were available in all of the various G bodies. You had 2 basic V6 engines ( Buick and Chevy) and 3 basic V8 designs ( Olds, Chevy, Pontiac-IIRC, no real Buick V8 was offered, just a very small Pontiac labeled as a Buick), and there seem to be enough holes down there to accomodate different mounts for most of them. The Chevy mounts are easy to get because almost all GM cars with a small block Chevy had the same clamshell mount and the block mount is common to any G body or F body with a 267, 305 or 350. B bodies may also use the same block mount, but I am uncertain. As for the suspension interchange, most parts should interchange except for a few specific exceptions you may run into like noted above. My car is a mix and match of an F body steering box ( with G body pitman arm) and the swaybars from both a Grand Prix SJ and a Monte SS. Size is all that matters here and the biggest ones come on cars with the 1.25 in front bar. The rear is .75 in , IIRC ( could be bigger IMHO to help the car rotate better in corners).