Ok....I've been trying to ID the rear axle in my '67 GS400. Everything I've read says that the car should have an 8.2" 10 bolt. Mine doesn't look like any of the other 8.2's I've seen posted here. I haven't been able to remove enough goop to get any numbers from the axle housing yet, but here's what I've found. My axle has: 2 parallel ribs running from the diff housing towards the pinion yoke scalloped 10 bolt cover the yoke is tapped for bolt on straps, not U-bolts there are two large, square lugs on the bottom of the housing there are two indentations (weld holes?) in the diff housing next to the scallops in the cover the area where the diff housing meets the axle tubes has 4 square bumps at intervals around the circumference I've read almost every post in the Got Gears? section, and the description above seems to fit an 8.5" 10 bolt, not an 8.2". I popped the rear cover and found a 2.56 open diff with the following markings on the ring gear: 1234476 41T16 GMC 1234476 The bearing caps are retained by bolts with 5/8" heads. The ring gear bolts have 3/4" heads. Both bearing caps are marked with a circle with an X inside, a sideways 8 (or infinity symbol), a large cast in diamond, and an arrow indicating which side they belong on. The left side bearing cap also has the number 152 on it. I tried to measure the ring gear inside the case, but wasn't able to get a good reading on it. Is this an 8.5 that somehow/somewhen got swapped in? o No: Thanks for any help...... Len
Len, Yes, your Buick has benefiitted from the swap of an 8.5 A-body rrear. The pics are of the most common '71-728.5 A-body housing, the one with the cutout rear cover & the big square lugs cast into bottom of the housing @ aprox 8 & 4 o'clock. Most of the '71-72 8.5 A-body rears were built as 2.56 or 2.73 singletracks, so no surprise with your 2.56 gearing. There is a huge aftermarket support for the 8.5, so desiring lower ratio quality gears & new HD posi, & aftermarket axles, the parts are easily available. Got Posi? :3gears: Roger
Woo Hoo!! :TU: Yesterday was "I found more rust over here" day......it's nice to get some good news. Thank you for the info Len
