67 grand prix 8 lug wheels replace?

[Midland John]

I have  a 1967 Grand Prix with 8 lug rims and a posi rear end. My new motor is a 428 aprox 450 hp. Would this posi be strong enough? Would I be better off converting to front discs and drum rears with an upgraded posi?

Thanks

John

[Frosty]

My answer is yes since the motor is producing as much or more raw horsepower than stock. The big Pontiacs in '67 had anything from a tall 2.29 economy gear to a low 4.11 gear. So an upgraded posi is a good idea. You can re-build a stock 10-bolt to handle the power of the motor, you just have to select the proper hardened parts. So do your homework!

The eight lug drum brakes are nice looking but they are still 4-wheel drum brakes. Bringing a speeding 4200 lb behemoth to a stop is better suited for disc brakes. You will have to convert all wheels to 5-lugs, this means buy a new set of wheels in the deal. This is not a cheap conversion but it will be worth it.

Edited October 26, 2016 by Frosty