Gear ratio with 37" tires

[Madgyver]

What do you run?

4.10 is not really working for me, I see 4.88 coming in..

I have a 4.56 3rd member all set up with LS but I would need to steal it from my Torino. I really don't want to do a double job. I'll just set up another one with a detroit but I can't make up my mind. I'm leaning towards 4.88 but I want to keep up with the traffic on the freeway.

It's the drop in RPMs between 3rd and 4th gear that I don't like. (NP435)

Give me some of your thoughts on this....

 

[ponypower77]

I think 4.88 would be better for the 37's.

 

[SaddleUp]

I run 456's in mine but I would happily swap to 488's if I didn't already spend the money on the current gears. I noticed some loss of snap pulling from stop signs when I swapped from 35's to 37's which I would like to have back. If I do go back into it I'll probably go clear to 5.11's/5.13's but I don't expect it to run out at 70 on the freeway if I do. Based on what you've said I would go with the 4.88's.

 

[66Gasgrill]

I run 4.88s in my green one 6banger w/np435. It doesn't see much street use though. My red one had 4.11s w a 351w and a c4, we just swapped in a set of 4.56's. gave the truck a much better feel. and still only turns 2700 RPMs at 65 mph. If my figures are right 4.88s would probably jump your highway RPMs 300-500. Is my math about right, does yours turn about 2300-2400 at 65? Oh both trucks run 37's HTH Most the stuff I have read say that 35's -4.56s, 36-37's-4.88s 38's-5.13s ect.. will bring you back close to a stock final drive ratio ie. 235's -3.50's

 

[mountainview68]

I am runnning 4.88 with 37's. I agree with 66gasgrill. Depends on how much driving on the highway you are going to do. Mine runs around 3200 pm at 65 with and auto.

 

[bax]

I say once you get to 37'' tires, you are most likley not do to much 70mph driving. I would have 5.13 gears no question. Let the big dogs eat.
Bax