My Brother found a great Posi Diff for his 70 Cutlass, but it has been modified and is 3/4 narrower than Stock. He's going to keep his stock SSII wheels, so we can't go wider on the tires.
Can we just use wheel spacers, or is there a reason no to do that???
Anyone know the in's and outs of all this??
Thanks!

 

3/4" per side our total? Since Olds wheels are lug centric, my only recommendation for peace of mind would be to have a hub centric set made. These would be hub centric to the axle flange and wheel.

http://www.motorsport-tech.com/

 

Your wheel studs probably won't be long enough to engage fully with a spacer. You'd have to get longer wheel studs to make it work if you want to use them. I've also seen wheel spacers that bolt to the axle but have their own studs for the wheel. So basically 5 holes and 5 studs.

Having said that I'll just add I'm not a fan of wheel spacers. It would scare me. Is the rear end 3/4 inch shorter overall or each side? Overall it would not be much of a problem with say using a 1/4 inch spacer. Rule of thumb is you want 1.5x the stud diameter minimum engaged in the lug nut.

 

I would advise against it by all costs, especially if he plans to romp on it from time to time.

 

Thanks everyone......trying to find out right now if it's 3/4 overall, or on each side. I've never liked the idea of doing anything like that either. You all just confirmed my "gut" feeling about the whole thing. I'll post again when I have more info/make a decision.

 

Here's the scoop,...This is a Pontiac posi diff out of a 66 GTO. The guy changed the spring bases to be correct for a 67-72 A body, and had it in his 67 Lemans. It's actually maybe 1/4 narrower than the 12 bolt "O" in the Oldsmobile right now. It "should" bolt right in, but now my concern is the yoke is different. The one on the Pontiac is a 27 spline. Anybody know off hand what it is on the 12 bolt and if they are interchangable?

 

Do not confuse die cast Chinesiium spacers with properly machined hub-centric spacers. I've run a set of 2" spacers on my dually for nearly a decade now. I got them here:

www.wheeladapter.com