Dan, Try this tranny
If you want a low gear 5 speed try these combos. Get an 81-83 5 speed and swap in the input shaft and front countershaft gear from a 79 5 speed for these ratios:1st, 3.422:1 2nd,2.0765:1 3rd 1.46126:1 , 4th 1:1 , 5th 0.8326:1. This next one has some killer low end acceleration but there is a huge gap between 3rd and 4th gear. Swap in a 74 260 input shaft and front countershaft gear on to a 81-83 5 speed for the following ratios. 1st, 3.706:1 2nd,2.245:1 3rd 1.58023:1 4th, 1:1 5th 0.9004:1. Combine either of these tranny combo's with a 3.9 rear end gear for outstanding acceleration. Later,norm