/6 questions

My information shows a 20-7.50 has a 41 inch diameter, so with 7.17 final you'd be running 3500 at 60 miles per hour and with the 5.23 overdrive ratio 2570 at 60. There are many kits to put a GM automatic behind an AMC engine, if you wanted to go overdrive automatic. I think the \6 AX15 is my favorite combination, even though the transmission is a little light, your not going to be pushing it past its torque capacity with the \6, use one out of a Dakota and it should swap pretty easily to a \6 iron truck bellhousing for an NP435 and 11 ind HD clutch. Ratio spread for an AX15 is 1st 3.83:1; 2nd 2.33:1; 3rd 1.44:1; 4th 1.00:1; 5th 0.79:1, and Reverse 4.76:1. The AX15 was a replacement for the NV2500/NP535, but I wouldn't give it a second thought, being that the AX15 was an upgrade. THe AX15 upgrade was the NV3500.