Ok so I did my 5 speed swap with a TII drivetrain (including TII shaft) and modded my 3.90 (S5) rear diff to accomodate it. Now I need to ditch the 3.90 open diff for a 4.10 LSD. I have the option of swiping one from a '88 GXL. First question is will the S5 N/A shafts fit? And can I take the modded flange off my 3.90 and put it on the 4.10 N/A? Also I kinda have a S4 TII rear diff and shafts. See I pulled them from a TII parts car and my friend said the S4 TII diff won't bolt up (?). I think he knows better. I just think he wanted to keep it since I let him keep parts I didn't need. If it will bolt right up then I'm going to snag it back. My question is will the S4 TII rear diff and shafts bolt right into a S5 N/A?

 

yeah, s4 or s5 TII drivetrain will bolt on to any fc rx7