engine swap

i have a 1989 s-10 with a 4-3 v-6 regular i want to put a 4.3 vortec in it out of a newer 90 model s-10 what do i need to do electronicly if anything can i just drop it in and plug it up or do i need a new computer and wiring i hope not but i geuss i need to find out before i try it