1972 c10 ring and pinion swap.

[JCoop72]

Hey guys. Probably been asked 1000 times but here's 1001.

I have a 72 lwb c10 with a sb 400 and th350 trans. Putting out 530 hp at the flywheel. I have 3.08 rear gears right now. What would be a good gear swap. I was thinking 3.73. Maybe 3.42. Any suggestions??

[mike16]

I currently have a 72 with the 373 gears. about 5% of the time they are great for hauling. the other 95% of the time I wish I had an overdrive gear.

I dont suppose youl be hauling fire wood, cinderblocks or old cars with it.

you will be greatfull for the better milage and the current(?) or future use of an overdrive with a 342 gear set up. Your 308 differential "case" is compatible with any gear ratio bellow 373, so to choose a 342 ring and pinion will save a bit of money there, but 373 diff cases are quite common too and ought not to cost much either.

tough call . I like my 373 gears but sure wish It was more hiway friendly that 95% of the time.

[JCoop72]

Originally Posted by mike16

I currently have a 72 with the 373 gears. about 5% of the time they are great for hauling. the other 95% of the time I wish I had an overdrive gear.

I dont suppose youl be hauling fire wood, cinderblocks or old cars with it.

you will be greatfull for the better milage and the current(?) or future use of an overdrive with a 342 gear set up. Your 308 differential "case" is compatible with any gear ratio bellow 373, so to choose a 342 ring and pinion will save a bit of money there, but 373 diff cases are quite common too and ought not to cost much either.

tough call . I like my 373 gears but sure wish It was more hiway friendly that 95% of the time.

Well this truck is gonna be a fast show truck. I was worried about the 373 with the th350 not having an overdrive gear. Idk if 3.08 is gonna be fun enough though. I'm considering 3.42 now then.

[trkfrk]

Here is a great gear ratio chart you can use to help you decide. You can play around with different scenarios.

http://www.grimmjeeper.com/gears.html

[JCoop72]

Originally Posted by trkfrk

Here is a great gear ratio chart you can use to help you decide. You can play around with different scenarios.

http://www.grimmjeeper.com/gears.html

I appreciate it. That helped me out a lot. I think I'm going to order 3.42. I like the middle range that it offers. Just in case I do drive it anywhere

[mike16]

I had a BBC 67 Camaro with 308 gears.a bit sluggish on acceleration. I think the 342's would be a good bet.

[JCoop72]

Originally Posted by mike16

I had a BBC 67 Camaro with 308 gears.a bit sluggish on acceleration. I think the 342's would be a good bet.

Yea I think it's he best bet. Won't have to change carriers either. My posi unit is in good shape.

[Jrainman]

I just put a 3.08 in my 68 about 3 weeks ago , it had a 3.73 this is a DD and travels the interstate everyday the SB 350/th400 with 3.73 combo hated the interstate above 65 mph .
So I put 3.08 in and now I can push the truck with ease to 100 mph did not really feel that much different still pull up hills the same and still Lites the tires up from dead stop till she shifts in to 3d .