Gear install problems? ring gear spacer???

[FirstGen]

Anyone ever used a ring gear spacer to go from a 3 series carrier to a 4 seriers? Are these the same for the car as for the truck?

I have a Mr.Gasket PN #902A and when I tighten up the main cap for the carrier with my 4.11's they freeze up...

Any ideas? I put a new bearing from Napa on the pinion and installed with the old crush sleve. Then I tried to bolt the spacer and the 4.11 ring gear on my 3 series carrier and it spins well all the way up till the very last thread on the main caps like the pinion is too far back??????

I have no idea what is going on here... any help is appreciated.