can a 92-93 b18a1 replace my 90 rs b18a1??

Just wanted to know got a pretty sweet deal on it but im not sure if it will work???

Yes, that will work fine. You’ll need to swap some parts over from your original motor (distributor and wiring to mention a couple) but that is all very straightforward.

The topic has been covered a lot, you should be able to search for all of the info. Basically you just need to deal with the fact that 90-91 is OBD0 and 92-93 is OBD1.