I currently own a b16 cable trans with a cracked housing and i also own a b18 cable trans, i was wondering if i could swap all my b16 internals into the b18 case and use the b18 5th gear instead of the b16 5th gear for gas milage. I was planing on putting a lsd in at the same time but i dont know if cable and hydro differentials are the same? and input would be helpfull.

 

It depends on what model cable transmissions you have. The 88-91 Y1/S1/Y2/A1/J1 all use the same housings and the 92-93 YS1 B16/B17/B18 all use the same housings. You can not interchange the early model (88-91) with the later model (92-93) as they are completely different internally.