So I have a 12-bolt in my '86, came out of a '73 I think, 1/2 ton. I think maybe it was called a "heavy half". Anybody know anything about these? Any good for performance use? It has took everything that the stock 305 could throw at it, and so far has took the 350, but I just want to know whether I should spend my money on it, or something else. I have noticed that there aren't many aftermarket limited slips for it, just lockers. Maybe it is more of a 4-wheelers rear?..

 

anyone?

 

12 bolts are indeed an excellant differential. Moser does some real nice 12 bolt conversions for the F-Body guys... guys that are well over 700rwhp and pulling the front wheels off the ground at the starting line. Lots of good aftermarket parts for the 12 bolt...

Bill

 

Yeah, I know there are lots for the car diff. but I can't find anything for the truck diff.. I know they have different part numbers for the carriers themselves, and the gears, but what else is different?

 

I'm willing to bet the ring gear size is different as well as the axle spline count.

 

The ring gear size is the same at 8.875, and the spline count is also the same, at 30.. I think I remember hearing that the pinion was a different diameter, but I'm not sure..