SupCrewHunnnnay

yes, I used the search feature...but nobody mentioned the gear ratio in question


I have a 2002 S-crew with 285/75r/16's...in the next week, I will be putting a 2.5" (front) 1" (rear) rough country lift/level on it.

two questions: will I be able to fit 315/75/16's on it? I assume so since guys have dropped 35's on it with the t-bars cranked...but more importantly, will it jack up my 3.55LS rear end too badly to drive it with that large of an increase in tire size/weight?

fyi, stock tire size for my truck is 255/75r/16

MGD

Hi.

First - which engine? It does matter.

I'll defer fitment advice to others. Some trimming may be involved, depending upon the tire profile.

However, yer truck WILL be a dawg - especially if it's anything but a 5.4.

Yer trans will be stressed, yer odo, speedo and shift points will be off. Yer mileage will plummet and yer braking distances will increase. And handling will be altered.

At the very least, get a good programmer to help with this. Best recourse is both a programmer and regearing to at least 4.10's, with 4.56s much preferred, to get yer effective gearing and loss of torque multiplication back in the ballpark.

If all of that is understood and yer cool with it, go for it.

good luck
MGD

SupCrewHunnnnay

thank you for the reply...I have the 5.4 and a SCT Livewire, which I used to fix my spedo when jumping from the stock size to the 285's I have now...is the regearing going to be necessary? any idea how much that's going to run me?

Jackedup00

Mine is on 37s with 3.55 gears,the rear end will be fine the trans will have extra wear but not too bad with those tires. And it won't be a dog,mine moves just fine

Bryan95

My truck is on 33's with 3:55s and it still feels a little doggy. I couldn't imagine 37s

Jackedup00

My brother inlaw has 33s and a 5.4 and my truck when its running right will run side by side with him. When my truck was running perfect he said it would probably beat his truck

SupCrewHunnnnay

right now, running the 33's (285) it feels like I lost a little pep, I would agree with Bryan95...that's actually the origin of my inquiry. I felt a little step down in first and second gear, notsomuch later on...just taking off from a standing stop.

Jacob.P93

I call total bs I don't see how this makes sense to you.

charliedyal

I'm running 37's w/ 3.55s and I'd put it up against one on 33s anytime. I'm not saying gears don't make that big a difference, plan to swap to 4.88s when finances allow, but when a 5.4 is built and tuned proper they make plenty of power. I don't believe he's BSing.

Jacob.P93

Haha I honestly am lost for words here.