BBC in 72 GP

[nonni400]

Hello,

I am rebuilding a 1972 Grand Prix and am thinking about putting in a 502 bbc and a built 700R4 transmission, what engine mounts would I be able to use and does the frame need any mods.

Thanks

[engineer]

It takes special mounts for the pontiac engine in a GP because of the long nose and center of gravity, so I doubt the BBC will be easy.

[red76TA]

put a 455 in there- will be much easier and for what you spend on a new 502 you can have a real bad 455

[FrankieFeenixx]

I would imagine you could just use motor and frame mounts for a big-block Monte Carlo. The trans mount would probably have to be modified.

[engineer]

the pontiac GP mounts are welded in and offset over the frame. Since the GP is longer than Monte Carlo, the BBC mounts would put the center of gravity in the wrong place if installed like the MC.

[Mantra]

Why would you do that anyway?:confused:

455 all the way!!!!

[engineer]

because the MC mounts connect to the BBC in a different relative position in order for the oil pan to clear. If you mount BBC in the Pontiac position, the oil pan will hit the frame crossmember.