alright the transmission shouldnt be a problem, there both hydraulic, OBD1 and OBD2 B16s are both hydraulic ( USDM side atleast, the B16s in the del sols were OBD1 and the 99-00 Sis were OBD2 )

I dont really get the question? it should be pretty obvious to drop the OBD1 in a OBD1 car.

theres really no point what so ever to put the the first gen b16s in your car, youd need to convert from hydraulic to cable, OBD issues, are just somethings that can go wrong. It would be a lot cheaper to just get the 92-95 B16s