The back of my GSR tranny blew out where it gets bolted to the rear bracket on both bolts. I have a spare LS tranny that needs a diff, I have another diff, I have a spare S4C gearset and the back case, and a GSR tranny that the guy said doesn't move...

Basically I want to put a rear case on the one GSR tranny, make a B16 tranny with an LS 5th, and rebuild the other GSR tranny.

I need to know if hydro LS diffs are the same as B16 diffs? I also need to know if you can use any hydro case on any hydro gearset/diff? I was wondering if all the synchros were interchangeable as long as they are from the same gears so that I can minimize costs and grinds at the same time?