If your plan to to put the Muncie 4 spd, then while I was changing to a posi, I would put the 3.36 gear in. I think that was the highest gearing available with the 4 spd. That will put you around 2700-2800 RPM @ 60 with correct tires and wheels and you will have enough gear to pull out with on a hill. My swapped 2.73 could not pull out on a hill at all and had to get the correct 3.36 gear. I think the 3.36 is a happy medium for me.