so i have a stock 98 ram 2500 ext cab 4x4 that i wanted to lift. i have already ordered a 5" lift for it and i was woundering what i can fit on it for tires. i was thinking about going with 37s but im not sure what i will need for a backspaceing or offset. im prety sure the tires will rub if there on a stock rim. any advice at all would be very helpfull

 

Don't go to 37s (if you can even find a rim/tire setup that won't rub) if its an automatic and has stock gearing in the axles. That big of a tire will cook the tranny and the truck will be an absolute turd when it comes to power for towing and acceleration. If you have 4.10s from factory, the biggest tire i would go is 35". If you have 3.55, then you will really notice the power loss if you bump up to a bigger tire. Switching to 4.56 or 4.88 would be better. This will also save your transmission.

 

Posted in wrong forum, moving to tech section.

 

it is simply mathematics. calculate the scope of your tire now an then.
(maybe scope is the wrong word, i'm from switzerland, i mean with "scope" the distance a tire made during one revolution).

if ne new tire has a 20% bigger scope, you will loose 20% of your enine power and 20% of your breaking-power.

 

You will clear the **** out of some 37's. Here's a pic of my 2500 the day I got 35's on it. 2" spacers up front. Completely stock otherwise. 16x8's w/4" backspacing.



I have an NV4500 with a kevlar clutch in that truck, with 3.55's. What everyone else said is correct, you will need to re-gear. 4.56's at a minimum. I would recommend 4.88's. That's what I was collecting parts for before I was in a wreck in that truck.

 

thanks everyone this has been very helpfull and has given me lots to think about. i wont be lifting the truck till spring so i have some time to think if i want to change the gears or not( right now it has 4.10s) thats something that i never even considered, and how big of tire i should go probably 35s if i dont change the gears....

 

35's on 4.10's is not a bad combo. You will see some power loss for sure, but at least you don't have the crap 3.55's most of us got stuck with.