91-95 should be a direct swap. You could use any block till probably '02. After '02, there might be some needed mods to the engine mounting brackets. You should be able to a RENIX (87-90) block. Just remember to reuse your electronics and fly wheel/flex plate. I thnik there is an additional temp sensor in the 91-95 head that the 96-99.5 head. In mid 99 the smaller exhaust ports showed up.
Tom
Tom
