3.08 to 4.10 first time swap

[HotRodPC]

I noticed Yukon makes a 3.90 ratio for the 10 bolt 8.5 the other day when I was looking at gears for someone. I had 3.90's in my 62 1/2 ton Chevy PU. I really liked that ratio alot. A nice split right between 3.73 and 4.11's. With a 31in tire and a close ratio Muncie 4 speed with a real 1 to 1 ratio in 4th, it was good enough for freeway driving when speed limits were 55 and I usually drove it about 60-62mph to stay outta trouble but still enough low end torque to light'em up with ease and get a mean sideways 2nd gear. Only problem I had was tearing up spiders and snapping driveshafts. Finally got that rectified when I got the 64 GMC 3/4 ton with 4.56's and LSD in the Dana 60 rear end. Miss both of those trucks and all the power. Miss my 4 speeds alot too.

 

[Camar068]

I noticed Yukon makes a 3.90 ratio for the 10 bolt 8.5 the other day when I was looking at gears for someone. I had 3.90's in my 62 1/2 ton Chevy PU. I really liked that ratio alot. A nice split right between 3.73 and 4.11's. With a 31in tire and a close ratio Muncie 4 speed with a real 1 to 1 ratio in 4th, it was good enough for freeway driving when speed limits were 55 and I usually drove it about 60-62mph to stay outta trouble but still enough low end torque to light'em up with ease and get a mean sideways 2nd gear. Only problem I had was tearing up spiders and snapping driveshafts. Finally got that rectified when I got the 64 GMC 3/4 ton with 4.56's and LSD in the Dana 60 rear end. Miss both of those trucks and all the power. Miss my 4 speeds alot too.

lol dang it....and I was at a toss up between 3.73 and 4.11/10. And now I see this. Been wondering about the 3.90.

 

[HotRodPC]

lol dang it....and I was at a toss up between 3.73 and 4.11/10. And now I see this. Been wondering about the 3.90.

For you.. Being you have the 700r4, I'd for sure go 4.10/11s. Especially being Fo Buh Fo and potential to run taller tires. It would be no question for me. 4.10's for sure, and being 4x4, I'd be tossed up between 4.10 and 4.56 but would likely choose the 4.10's due to being more common and if I broke either the front or rear the 4.10 is going to be easier to find, and maybe even a good chance for a good used one ready to roll, or if I chose to upgrade the rear axle to 14B FF later on down the road, 4.10 is pretty commonly found in the 14b Full Floaters, and then my front axle is already matched up, just have to convert the hubs to 8 lug and done.