Will an oil pump of a b18b work on a b18a?

 

yes

 

Depends on what year. All OBD2 B18 oil pumps from 96-01 including LS/GS-R/ITR are the same. You can use them on OBD1 B-series but you have to modify the lower timing belt cover.

I believe an OBD1 B18 pump should work on a B18A, but I'm not 100% sure.