ive heard that the turbo models come with different gearing in the rear diff, i just swapped in a 5 speed d/r from an 88 spfi, before i get rid of the donor car is it likely that the gear ratio is different? car isnt running yet or i would just drive it and check.

Look at the diff tag and see if the two are the same. My turbo has 3.7 on it.

Turbo is 3.7:1, non-turbo is 3.9:1. You'll have some major issues in 4wd if you leave the 3.7 rearend in with a 3.9 front.