Questions about a possible axle/gear ratio swap

[grampadirt]

And don't forget whatever gears you put in the rear you'll have to put in the front diff,they must match to use 4wd.

 

[slowburb]

And don't forget whatever gears you put in the rear you'll have to put in the front diff,they must match to use 4wd.

Yes. Meant to say this myself.

 

[df2x4]

I've never, ever, said, "man I wish I had less gear in this".

I have, but it was after I put 3.73s and a TrueTrac behind a non-OD TH350.

Seriously though, all these guys are right. If you're going to do it, do it once and do it right. Re-gear front and rear to 4.56 or better, and get rid of the G80 in the rear. I recommend a Detroit Locker.

 

[Jrgunn5150]

I have, but it was after I put 3.73s and a TrueTrac behind a non-OD TH350.

Seriously though, all these guys are right. If you're going to do it, do it once and do it right. Re-gear front and rear to 4.56 or better, and get rid of the G80 in the rear. I recommend a Detroit Locker.

lol, I learned the lesson actually, putting 3.73's in my 70-something F-150 with 35's... From 3.55's... Great waste of 1,100 bucks that was. I mean, I got a Detroit in the little kit, so that was nice, but the front TrueTrac was worthless, and the gear's were still way too tall. I finally found 3rd gear low range to work out well, but I should have listened to my uncle and put 4.56's in that truck.

 

[5spd Z71]

If you use your truck for towing or hauling, you'll want 4.56 gears at the very least. If this truck is going to be nothing but a highway/DD truck ( which is pretty stupid to be lifting with 35's and not "use" it for anything, but that's just me IMHO ) I would consider a 4.10 gear. But then if you have to use it for a work truck, you'll regret that decision pretty quick.

I went from 35's and 3.42 gears and a G80, to 4.56 gears and an Eaton locker. Night and day difference. If you are going to regear in the future, spend the money and get some good gears. I went with Yukon gears.

 

[slowburb]

4.10 and 35's is like stock tires and 3.08's. Bad idea with an overdrive transmission

 

[99K3500HDCCLB]

these guys are right. Fuel economy is going to suffer a bit. My concern would be torque as that is what gets you most trails and off the line at a light. I used to have 42"s with 4.88s and nothing changed fuel economy when I went from 4.56 to 4.88 I saw a big torque help and it kept me in my HP range fairly well but 5.18s would be the real step for those size tires. Currently on my truck now my goal is 36in and 6 inches with fender flares. I have 32's now and its getting 15 and 12 in city.