Looking for some input from people with a similar truck or situation. We bought the truck a few years ago and have been rebuilding it since. Step by step we have taken this thing from a beater mud truck to where it sits today.

Motor has plenty of power but I think the bigger tires are affecting our off road and towing abilities. It has stock 3.55 gears, dana 60 up front and sterling 10.25 in the rear. We drive the truck in the summer for towing our camper, and heading up to the sand dunes. We drive it between 2-5 thousand miles a year due to our jobs and the weather here in Michigan. Truck is not abused off road but we want to be able to get the power to the ground. When towing we keep it right around 60-65 mph, on the dunes we barely go above 30.

I want to find the hill climbing power I know this truck has, but I think the gears are holding us back. Wondering what gear set would get us up all the dunes and be great for towing. 4.56 or 4.88 or?

 

Nice rig... I wouldn't go any lower than 4:10 , you may lose your hiway cruise anything above 60mph with lower gears your 460 gonna get more thirsty.

 

Not really a highway cruiser. Right now we can easily go 100mph if we wanted to but no need for that speed. Like I said before 60-65 is the top speed this truck will see. Not a daily driver, and we are well aware of the gallons per mile capabilities of our 460.

 

The C6 doesn't have an overdrive or a lockup torque converter, so you don't want to go too low with your axle gears or your mileage will plummet and it'll be less pleasant to drive on the highway due to engine noise.

That said, you're pretty tall now. 3.55 gears at 60 mph put you at 1930 rpm (higher really due to no lockup torque converter). That's not too bad for mileage, but it does mean you'll need to downshift to get up hills with a load.

4.10 gears would put you at 2300 rpm at 60 mph. Probably a good place to be if highway driving was your only concern.

4.56 gears would put you at 2480 rpm and 4.88 gears would be 2660 rpm. Getting pretty "buzzy" at those speeds, especially if you want to go faster (70 mph would be 2900 and 3100 rpm, respectively).

But you also want to be able to drive dunes in 4WD at 30 mph. I'm not sure what your transfer case low range is (you do use low range, right?), but it's probably pretty close to 2.6:1. I'm also not sure what gear you wasnt to use on the dunes, or what the C6 ratios are in 1st or 2nd.

But assuming you want to be in 3rd gear at 30 mph in low range (and assuming 2.6 t.case gears), 4.10 gears put you at 2900 rpm, 4.56 gears put you at 3230 rpm and 4.88 gears give 3457 rpm.

I haven't driven dunes ever, so I can't give recommendations there, so I'll just leave it with that data.

 

4 low in the transfer case is 1.96:1 on this truck

 

Not to highjack the thread but what size are the wheels and tires. On your truck.

 

375/65 r16 (36x15.50) tires on 16x12 rims.

 

Awesome thank you.

 

you are about rite on the gearset choices, either the 4.56 or 4.88 will serve you well. i have a diesel with C-6, 4.10 gears, and 37 inch tires on it and wish i had a lower gear.

 

I would choose 4.56 for that application. 4.30 would be even better, however I don't believe that ratio is available for your axle pair. 4.88 would be too low if you ever plan to drive it on the highway much.

 

This truck probably sees the highway 300 to 500 miles a year. Back roads are abundant and easily get us everywhere we need to pull the camper or travel to. I appreciate all the input, thanks guys.