I know first gear is like 3.90 I dont know from there. Also is there a place on the rear that'll tell me my rear gear ratio? It's still the 7.5" rear. I'm guessing it'll be anywhere from like 2.73 to 3.27
There's a T5 identifier near the bottom of the page. Get the number from your transmission tag and pick it from the list. There should also be a tag on the cover bolts on the rearend.
If you have an 88 7.5" rear end. The manual will have 3:55 and the 5-speed will have 3:73... I got 3:73 gears and a 4 banger T5... It gives one hell of a ride in town but highway sucks. I'm having fun until it lasts...