4.10's with 33" tires?

[80 Chevy K20 4x4]

I was wondering if anyone here on the board has a 4x4 with 33" tires, 4.10 gears, and a turbo 350 or 400 trans. I want to know what rpm your rig runs at 60 mph and what kind of gas mileage you get.

Thanks,
Doug

 

[Muddytazz]

I have 4.10's and 33's in my burb but can't answer because I have no speedo, my motor is pushing 375,000 miles and my carb is all f'ed up.

 

[tRustyK5]

Should run at 2650 rpm, mileage would be between 9-12 would be my best guess.

Rene

 

[sweetk30]

are you looking to whip the ricers on the street? sounds like a good combo.

 

[fatbob]

Rene nailed it pretty good.

I had a 77 3/4T carbed 400/400/205 4.10 with 33 BFG muds and it turned about
3000 rpm at 65mph. I got 10-11 miles per gallon. Next time I would go with 35"
tires.
Bob

 

[80 Chevy K20 4x4]

Actually I'm thinking of trading my 87 Silverado 3/4 ton LWB 4x4 to my brother that has a 79 Scottsdale SWB 4x4 that has 3.73 gears with 33" tires. A good friend of mine used to own the 79 Chevy and I used to work on it when he needed something done to it. I'm just wondering if I should pull the 3/4 ton axles out of my 87 and switch them onto the 79? I'm running 4.10's with 33" tires on Weld Racing wheels on the 87 and my tires are way better than what's on the 79 Chevy. I'm gonna drive the 79 tomorrow and see what the rpm is at 60 mph. I used to have a 74 Chevy sWB 4x4 with a built 396, turbo 350 tranny, and 3.73 gears running on 35" tires and it would run 2650 rpm at 60 mph. I just wanted to know how much of a gas mileage loss I'd take if I ran 4.10's and 33" tires with no OD tranny.

Thanks,
Doug

 

[70~K5]

When my '77 K20 was stock it had 9.50x16.5 tires and 4.10s. Sb400-th350-np203 too. I got around 10- 11 mpg on average. I changed the tires to 33" 12.50x16.5s and it was fine but didn't pick up that many MPG.
A friend had a '78 K30 454-sm465-np205 w/4.10s and he got 8 mpg empty or loaded.