[dockrocker]

I have 35's on my truck with the stock 3.73 gears. Doing the math it looks like it needs about a 4.30 gear to be back to the stock gearing. I doubt that gear ratio is available for these differentials. I think 4.56 is a little steep and not sure if 4.10 is worth the money to change. Is anyone running 35's with a six speed with 4.10's?
I just got back from a 2500 mile road trip and noticed that running in 5th gear it picked up just over 2 mpg over running in 6th. There is about 300 rpm difference and I think that is about where it would be with 4.10 vs the 3.73 even though it would not have quite the effective ratio it came with from the factory, and it seemed really good from the factory. Just wondering if anyone else has been through this.

 

[sickpuppy]

I called west coast differential and they told me 35s with 4:56 would put the rpm 125 over stock with the 245 tire.

 

[liftlawssuck]

do you tow alot if so then go with 4:10 if not then stay where u are at?

 

[Grit dog]

W/ the big tires, 5th gear should be close to what 6th is on stock tires. Unless you're having trouble accelerating in the lower gears, a gear swap seems quite involved and costly if you could acheive the same thing by running in 5th on the highway.

 

[dockrocker]

Thanks

I haven't had a chance to get back on here till now, thanks for the replies. I have an appointment to install gears Wednesday. I am going to 4.56's and after doing the math it looks like it will be turning about 150 more RPM at highway speeds. I think I might go with a little larger tire in the future and the additional gear should make life easier on the transmission. Might even have to try the "extreme" setting after the gears and see how that works! I will reply after the gear swap with "real life" info in case anyone else is considering the swap.

 

[southbayrhino22]

I am considering 456 gears but running 40" tires.I overgeared my last truck and it would barely go 55mph in OD.It used more fuel than before gearswap.The only good thing is it would pull any trailer no problem.
My 6spd LBZ with 40s gets 10.5 mpg towing 8500lbs not regeared.It pulls way better than I expected without gears done.
Dockrocker if you could log down a couple different speeds vs rpm before and after the gears. I would like to see the difference before I choose gear size.
My truck currently shows 50mph on speedo when stock hd behind me says 65 Im at 1600 rpm in 5th with Tow mode on.

 

[GlenRoseFireFighter]

http://www.differentials.com/calc.html