Hello,

I have a friend with a 72 Buick Skylark with a 3.42 posi rear end. I believe is a 10 bolt, while mine is a 12 bolt with an open carrier 2.73. I'm not quite sure it will fit, and I believe this might be the weaker of the 10 bolts out there, but a posi with a 3.42 sure sounds appealing. My 'velle is under 400hp, does any think this is a good swap? Also I'm running a TH350 with 2500 stall converter. I don't have the funds to upgrade the 12 bolt, and this is a free swap. Thank you!

It's a direct swap. I wouldn't waste my time doing it. For lack of funds right now to get your 12 bolt in the shape you want it. If you grenade the BOP you'll be in the pockets much deeper. The only upside to the swap is the BOP axles bolt in like the ford 9's. The 12 bolt is considerably stronger so don't trade down. I'm sure he's chomping at the bit to swap even.

RandyB..

Also, I thought that there is a length difference in the drive shaft. The 12 bolt set up uses a shorter drive shaft than the 10 bolt, so if you are going to swap, make sure you swap drive shafts too.

But I agree with 31 chevy, don't trade down. Save some money and buy an aftermarket posi unit with a good gear set when you can. Good luck.

if it's an 8.5, it isn't really any weaker than a 12 bolt, and it has the benefit of the bolt in axles.