Hello, Can I get another set of eyes to verify the rear end in the pics. The car is a 70 Buick skylark, originally a 350 2 barrel set up. The PO dropped a 455 in it. From what I can tell the rear looks like a 8.2" 10 bolt. Is this correct? I found the marking LK on axel tube which indicates a 2.56 gear ratio. It has the single rib that runs down the side of the housing horizontally and is missing the big square lugs on the housing below the cover which disqualifies it as an 8.5 inch 10 bolt?? I had the cover off a while ago & did not do any detective work on the internals at that time. My bad. From everything I have read, these rears are built to handle around 400 HP. I want to move to a posi with stickier wider treads and my engine setup is 500+ HP. I don't want to throw money at this rear because I am afraid it will grenade at some point if the car hooks up. I am attending the Carlisle PA swap meet this weekend and want to pick up either the 8.5" 10 bolt or 12 bolt that will fit a GM A body car. Is it true that the 8.5" has a larger yoke which means I would have to shorten my drive shaft? Is there a turnkey rear I can put in the car with no additional modifications? I have also read that some 10 bolts had axels that were an inch shorter. I will do my due diligence and take as many measurements for the rear as possible prior to attending the event. Any advice that you can pass along for identifying and getting the correct application is greatly appreciated Regards Jim
8.25 Buick ONLY 68-70 era All custom parts to get that rear end done. Fabcraft gears 3.42 or 3.64 ONLY and they need to be produced. I have posi units to make the 2.56 2.73 2.93 3.23 3.42 stock ratios work. I have the posi units for the 3.42 and 3.64 gears also from Fabcraft. I have all the rebuild kit etc for this rear. If you are going to swap a 8.5 in for this rear you will need to shorten the drive shaft.
You need to find an 8.5" out of a 71-72 Cutlass/442 or 71-72 Skylark/GS.These are a great rear to build,have bolt-in axles(no c-clips),and plenty of parts available for them.Your driveshaft will need to be shortened 3/4"-1" Other than that,it is a direct swap.They even take the same 3R u-joint that you have now. If you don't find anything at Carlisle,I have cores here,and I can build you whatever you want.
