Gearing with 37s.
 

Im picking up a set of military 37 inch goodyears for my 93 dodge, and was wondering witch is the best gear ratio to run in these with bigger tires. I was thinking 4.10 but i dont think thats going to be deep enough. The truck is a automatic with overdrive I tow a 7K pound trailer about twice a month. Maybe 4.56s maybe?

4.10s should be about perfect, I had them on my obs powerstroke with 36s and it was just right. Running 70 i would turn about 2000k rpm, and i towed with it everyweekend 4-8k pounds without a problem.

Cool, thanks for the info! When i install the gears, i will also be installing a detroit locker front and rear.

No problem, sounds like the truck will be hoss!