I think the 0.72 overdrive will work fine and you'd be happy. Moparguy has that comb and is happy. You would be too. First gear will feel very low.
I rebuilt a T5 for a guy with a 55 Chevy coupe. He lives in Ohio and it's flat there. We decided he'd be happy with a V8 Camaro T5 with the 2.95 first gear and the 0.63 overdrive. He had a mild 350ci engine. He loves it. He also has plenty of HP with the 350 to pull that 0.63 overdrive gear.
I mention this because before I shipped that T5 to him, I decided to give it a test run in my 1965 C10. My C10 has a stock 230ci and a 3.73 rear diff. I have a T5 from a 1983 V8 Camaro in my 65 but my T5 has the 0.72 overdrive gear. As I suspected, my inline 230 didn't like the 0.63 gear on hills. It would slow down and then start to lug the engine. Whereas my 0.72 overdrive gear does fine in the same situation. If you happen to find an early V8 Camaro T5 with a 0.72 overdrive, then grab it. It has all the gears you would want for excellent driving with your 4.10 diff.
Last edited by Lugnutz; 07/21/2017 6:36 PM.