94 S-10... whats the difference

since owning this truck in July... ive noticed it seems as if the 94 S10 Blazer is the red headed step child of blazers... a lot of performance parts i find end before 94 and start again in 96 - im sure that has a lot to do with OBD II but just to make sure before i go buck wild online and buy parts for the wrong engine... for example... the 91, 92, 93 .... 4.3L Vortec IS the same engine they used in 94 right??? i know OBD II started in 95 on those