i believe 89-91 will work, i heard somewhere that in 92 some things were changed around, more sensors and such, but since the motor is out of a 90 that would be the year that i would be lookin for
I know on the 3.0, I think it was 90 a bunch of stuff was changed. I did a swap, put a 88 3.0 in my 91 3.0, and I had to use my 91 connectors on almost everything. Had to swap out fuel injectors, TPS, several ground wires. and some other random stuff.
If I were you, I'd get the year that the motor came out of, but check out the 94 closely, to see how well the plugs and such will match up. As long as they'll plug up, I'd use the 94.