I have an f350 that I'm slowly converting to an F100. I'm building a 333 stroker Y block, I have a T5 tranny that I'm going to have John modify for me. I had a nine inch that I got for free that turns out is junk. So, I've been on the hunt for a rear axle. Ideally I was thinking about either a 3.70 final drive, for highway/freeway economy. But a 4.11 sure would be fun around town. So, the only pieces of info that will help you guys are the tire diameters- 30 inches. And the overdrive gear in the T5 is a .79.



With the 4.11 it wood put my RPMs right at about 2500 for 70mph.



What are your opinions on final drive ratio for my application. Will I be happier with a 4.11 for gunning an occasional street light. Or should I go with the taller gears for economy sake?

Heber City, UT (15 mins outside of Park City- basically it's in the mountains)

55 Effie