Does anybody have a suggestion for gear ratio to run 35s and 37s?

Baddad

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Nov 8, 2022
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Gallup, NM
Good evening!

I have a 87 yj that has been built pretty extensively. It has a LT1 motor, 700r4 trans, and ford 9 inch axles front and rear that have been narrowed and tubed and sleeved with wagoner outers up front. Previous owner said it was built for 37s, but needed gears to run them efficiently. Right now I have 4.56 gears on 35s but have noticed it doesn’t quite have the get up and go. Does anybody have a suggestion for gear ratio to run 35s and 37s?
 
Have you tried looking on MSD's website for wiring installation. have you checked all the fuses under the hood and dash. Lord knows what folks do to these things wiring wise to name one area of redneck molestation.
 
Have you tried looking on MSD's website for wiring installation. have you checked all the fuses under the hood and dash. Lord knows what folks do to these things wiring wise to name one area of redneck molestation.
Everything runs well how it should. It has a full harness installed for running gear.
 
35x3.14=109.9
109.9 inches /12=9.158 feet per tire rotation
9.158 ft / 4.56= 2 ft of travel per drive shaft rotation
5280 ft per mile / 2= 2640 drive shaft rotation per min. To do 60 MPH with 35” tall tires.
So in 3rd gear on your auto trans at a 1 to 1 transmission ratio, your engine should be turning 2640 RPM with 35’s at 60 MPH.
I would think that this would be within an LS engines good rpm range for decent power.
 
On 4.56 and 35's with the 700R4, you're already tach-ing 2200 at 70. If you have Wagoneer Dana 44's, then you should be able to go to 5.38 gears I'm pretty certain. 5.38 would bump the rpm up to 2600 at 70 which would generate good performance. You could still slap on 37's but that will reduce the rpm back down to 2450 which will still be better than what you have now but not as good as running the 35's. I would skip out on the 37's idea, and do 5.38 for the 35's.

I think with front/rear Dana 44's you could actually do 5.89, and then run 37's.
 
It's a jeep, gear it like a jeep. Throw the lowest gears you can in there and have a jeep that does "Jeep things".

Personally, I give zero ducks about top speed in my Jeep. I've never spent so much money to make a rig go slower 🤣

Gear that sumbich like a tractor.
 
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