37's/38's on a 4.2 HELP/SUGGESTIONS
 

OK....97 4.2 4x4 f150 219,000

right now ive got 5 inch rcx with 295/75/16 on 16x10 wheels....
i just got a 98 f150 8.8 axle on craigslist with 4.88s in it that im gonna put in my truck....so i want bigger tires...right now i can easily fit 315's...but i was thinking going bigger because of such a lower gear ill have...only concern is if that little 4.2 v6 has the balls for such a big tire....i really want a 37 13.50...but im wondering if i should just stick with a 315 because of my baby engine....please, suggestions, ideas, comments...

I think the 4.88s would be a good match to the 35s because of the 4.2 but I don't think it would be bad on 37s either though.

Yeah I'm scared I'm just gonna kill my truck. . Like rev it to high with 4.88s and 35s or just wear it out with 38s . . (All I can really find is a 38 15.50)

Are you planning on adding a body lift too man?

toyo open countrys come in a 38x13.50

That engine will be fine since you are going with the 4.88 gears. And I don't know what you plan on using the truck for, but if it is your daily driver I would go with the toyo M/T's. Good looking tire, aggressive enough for mud, and does great on the highway. Smooth, quiet, and long lasting for a mud tire.

Yeah I would do a bl if I did 38s . . . I have a commuter dd truck so I can play with my f150 . . I just don't wanna kill it. . It's got a lotta miles. . . I just wonder if the 35s and 4.88s would rev too high doin like 75

Do you have an automatic or manual transmission?

With 4.88's and 35's at 75 mph, an automatic in OD with the TC locked will be turning 2460 rpm, with a manual in 5th it will be turning 2811 rpm. Considering the engine redline is over 5000 rpm, you won't have any problem but the gas mileage is going to suck.

Thanks glc. . I have automatic. . So theoretically would my mpgs be better with 38s?

Nope. With 35's or larger, no matter which axle ratio you have, the mileage will suck, especially with a lift. Doesn't matter which engine you have.

Don't enter any 'tug O war' pulling contests! :devil:

That stock IFS is the next weak link as will the 8.8 rear, even with the V6... You'll be sending a lot of torque to those axles thru the auto and those low gears.. ;)

Good luck and have fun with it! :banana:

Mitch

i ran 46's with my 4.2l no engine problems. Gearing is everything

Yeah I know mileage will suck. . I hope it does improve in town though. . I think I might just go with a 35 . . I was just at my buddies house and his bro has 4 new 36 13.50s sittin in the garage . . Things are freakin huge . . I can't imagine a 37 or 38 on my truck

Just don't forget you need to change your front gearing as well.

Yeah I know. . I'm just gonna not put it in 4wheel until I do