So I'm doing the 5 bolt conversion on my '75 Monza and have run into a problem......the rear in the '75 appears to be a 7.5" rear....dimpled cover, 2 long bolts holding the torque arm on. I picked up both a '77 Starfire rear for the backing plates since the '75 Monza rear used small brakes, and an 88-89 era 2wd S-10 rear end to pull the axles from....Now, the rear covers between the Monza and S-10 rears are IDENTICAL, BUT....the S-10 axles won't fit in the Monza rear....the S-10 axles are a larger diameter and won't go thru the side gears....
So...WTF is the issue here? Can I use the side gears from the S-10 rear and swap them into the Monza rear? Did I get a halfbreed morphodike rearend from either the S-10 or the one in the Monza? Everyone says this is such an easy swap, and somehow I've got a train wreck here.....
I've seen that all '71-'75 H bodies had 6.5" rears....I've seen that all Monzas have 7.5" rears...who knows the TRUTH???
Heres another funny thing...checked the axle code on the rear in the '75....DB, which shows a 2.56 6.5"....checked the code on the '77 Starfire rear....DY, 2.56 7.5" rear...both these rears look IDENTICAL....same covers, same 2 large bolts holding the torque arm on...S-10 axle won't fit in EITHER....
Axle measures 1.20" diameter on the S-10 axle splines, 1 115-1.120 on the Monza/Starfire axles....the other thing that doesn't jive is that this is a factory V8 4 speed car, but it isn't geared as such.....the H body library talks about 2.56's with a V6 4 speed, and 3.08's with a V8 4 speed....
Figured out some of it....28 spline axles in the S-10 rear......so WHAT S-10 rears have 26 spline axles? This rear is out of an older S-10, which is what everyone says to use, so how the heck do you know??
I'm gonna go curl up in a corner and bawl now.....