Hello, think its finally time to regear. I only have 31s with no plans to go any bigger. The 4.10s now don't seem to cut it up here in the altitude of CO and all the hills we have. Will 4.56s still allow me to go 65 on the hwy at a decent rpm? Also can you recommend a good place to get 2 complete thirds with arb front and Detroit rear and 4.56s? Have looked at marlin crawler, JT differentials, and a couple others and is there any one you like better?

1984 P/U, 22r, 5spd

Thanks

 

with 31x10.50 15

at 65 with 4.65 your rpm will be about 2800

at 65 with 4.10 your rpm will be about 2550

at 65 stock 225/75/15 tires and stock 4.10 gears at 65mph rpm will be about 2800 . so 4.56 will put you at almost exact stock gearing

I used this online rpm calculator and this is for a 5 speed w56 trans http://www.car-videos.net/tools/spee...B1=Recalculate