Gears

[Quik8slvr]

1045009

i was wondering...my stock yj is equiped with 4.10 gears....after swapping in a chevy small block im looking to change gears, i'd like to keep off-roading in mind but this is more of a daily driver/street jeep that only sees moderate trails and beaches so a small sacrafice in performance isnt to big of a problem on the off road side...what i do want to do is to make it so i get better gas mileage, and increase my top speed to do this would i raise to like 4.83? or lower to 3.?? anybody have any ideas????[addsig]

 

[bob]

1045015

the lower the numbers the better mileage. also you have to do the frount end since it"s a 4X4. this gets very expensive. best thing, glass pack for a muffler, K&N air filter . it"ll take a long time to break even. Even if you do change that ring & pinon.[addsig]

 

[Quik8slvr]

1045020

if i swap gears im going to swap axels at the same time, already got $5,000 plus in the beast, whats another grand?? haha

[addsig]

 

[BobJ]

1045025

did you swap in the 350 already?



With that much power you'll wind up wanting to run 3.09s or 3.55s..



if you use lower gears (higher numerically) you'll get better accelaration..

if you use higher gears (lower numerically) you'll get a faster top speed



For the most part higher gears will give you better gas milage, unless you go too high in which case you'll have to rev the gears so much in the lower gears you'll get worse gas milage.



The only person who I can think of off the the of my head that is running a v8 in a Jeep has a Ford 302 and is using 3.55s to spin 38" Super Swampers[addsig]

 

[Natty]

1045035

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Another grand, ha, ha, ha. How 'bout two or three depending on the gears, axles, and all other stuff that can break along the line.

[addsig]

 

[Bounty__Hunter]

1045067

Easiest and cheapest thing to do would be to find a YJ owner who has a 5spd and 4.0L or 4.2L engine and 33" tires. These generally came with 3.07 axle gears, which would be just right for your auto transmission and 31" tires. Swap both axles between Jeeps and you will both benefit. Cheap and a LOT less labor

I had a 350 YJ with 3.07 gears, 5spd, and 33" tires and it was okay, your's will be better since you have an auto.[addsig]

 

[Quik8slvr]

1045149

any 4.0/4.2 yj or just of the 87-92 style? that sounds like a good idea, i want to have good acceleration, but the top speed/gas mileage is more important[addsig]

 

[Bounty__Hunter]

1045246

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Any YJ, '87 to '95, that has the 6cyl. and 5spd. Verify with the axle tag that it does have 3.07 gears before turning a wrench. The '95 will have larger u-joints on the front axle shafts, if that makes a difference to you. You've gotten by with the smaller u-joints thus far.[addsig]