"Only the V8 Camaro/Firebird T5s have the 0.63 overdrive. They also have a 2.95 first gear.
So your 4.10 rear combined with either a 3.75 or 4.03 first gear (found in T5s from V6 Camaros and S10 trucks) will make first gear seem like a granny gear. 4.10 X 3.75 = 15.375. Worse if the first gear is 4.03.
I will let you do the math for the V8 Camaro T5. It has 2.95 for 1st gear and 0.63 for 5th and is a close ratio tranny. Except the drop from 4th gear to 5th is a HUGE 37%."
So if I find a camero/firebird with a gear going from 3.35 to .68 NWC an I take it apart and install it in my S-10 case