Since no one has yet to hear back from FabCraft, I'll post here for a set and won't rule out a complete 10 bolt "ON" 3.64 rear. Thanks in advance!
They're getting hard to find and the last email from Fab Craft (shared w/you) was only slightly promising/optimistic.
It’s a little easier to make a posi unit for the FabCraft gearsets,due to the different series,but one can be made for the OEM 3:64’s. I guess it all depends on just how hard you plan on beating on it. You are running a stick,so that’s one. Obviously hitting it harder than a foot brake automatic. You are parking the original parts,which is wise.
Yeah - the last thing I need is the original rear end puking all over the place. I really wish FabCraft would start producing gear sets again but that's a ways down the road, at the earliest. Funny thing is: about 3 or 4 years ago, I had two complete original 3.64 rear ends available - and subsequently sold - by friends (somewhat) local to me but at the time, I had the tired, old 455 in the car and hadn't been bitten by the racing bug just yet.
If you're racing I'd put an 8.5 in and not look back. You'll have a bullet proof rear for much cheaper. You can save the 3.64 for another resto guy.
I have a 10 bolt housing out of a '71 or '72 Chevelle I could use if I went in that direction. Is that what we're talking about?
No the guys are suggesting that Buick 8.5 71-72 which differs from the Chevy versions. A 373 would be very close to the desired ratio.
Since you're keeping your original parts, why not put a chevy 12 bolt in? They can be built plenty strong, and either a 3.55, or 3.73 would work well with the torque that motor puts out
Chevy and Pontiac phased into the 8.5” very late into production. Very few had them. The Chevy version still had c-clips.
I believe the Center section is the same on the Chevy 8.5 just a different set of bearings and outer ends.
Actually,if you use the yoke that came on the Canadian 12-bolts,nothing. The yoke looks identical to the BOP 8.2” yokes,and uses the same 3R U-joint.
I was going to say possible different ujoint size, but I think driveshaft should be fine. You'd just have to get a 68-72 rearend for the correct backing plate to backing plate measurements. My car actually has a 69 chevelle 12 bolt rear in it.
