Crazy Cooter

Howdy Ya'll, I've got a couple questions and I'm hoping to get some good feedback. First things first, I'm stationed in Balad Iraq, and I cannot see/test my truck until I go home in June for R&R. Secondly, my truck is a 1997 F-150 XLT, Single Cab, Short Bed, 5.4L, 5 Speed Man., 4x4. Currently it's sitting on 305/70/16 (33x12.50) Mickey Thompson MTZ's on Mickey Thompson Classic Locks thanks to a 3" body lift. It is currently getting upfitted with a 6" SkyJacker suspension lift, which will give me 9" total clearance. QUESTION #1 - What's the biggest tire I can run without fender trim/cutting? According to Mickey Thompson's tire guide (www.mickeythompsontires.com) I can run 35's-37's no problem. Now most 6" suspension lifts recommend 35's (315/75/16) but I can tuck those as it sits. I really want to run a 38x15.50x16, but don't want to ruin the fenders. Any help would greatly be appreciated.

Okay, this "paragraph" is about the proper gear selection. I'm stuck between 4.56 and 4.88. I'm not worried about MPG, my main focus is on getting down the road during the week, and having a good hole shot when I'm at the mud drag track on saturday night! Now I'm not a 1st time builder, I know generally the bigger the tire, the lower the gear, but not in all cases. I will be using Detroit Lockers both front and rear instead of an ARB Air Locker or Eaton E-Loc. So, QUESTION #2 - What's the best gear for a V8 powered 5 speed with 35"-38" tires that is both driven on black top as well as raced in the mud? I've got people back home sceaming 4.56 is fine up to 40"s and then I have some saying if it's bigger than a 35, it needs 4.88...

If anybody could shed some light on this, I would greatly appreciate it!! Like I stated earlier, the truck is at home in Kentucky, and I'm in Iraq until June. The worst part is, I come home the week of the "Season Opener" and I'm already getting e-mails for people expecting me to race. I'm having it finished while I am here, so hopefully I can come home, throw some rooster tails, and win me another trophy!! Thanks again for all your time!!

ak_cowboy

37s are pushing it for size. The overall diameter of the fenderwell is right around 37", which is why anything over 38s requires trimming. I'd go with 4.88s since you want a holeshot and don't care for mpg. 4.56s would work, but people also roll 35s with 3.73s, just not the best idea.
Good luck and thanks for your service!

150guy

im rolling 37's with 3.73 fine

ak_cowboy

Exactly my point. What happened to your 0-60 time and low end though?

150guy

mmmm ill have to test it but its not slow i spank all the z71's at my school on and off road =D i would almost say i have more low end than top maby itsw just me but im not going to regear 3.73 is plenty and i can roll 1.5k rpms at 70-75 gotta love that but if gas is no proble hell get as low as you can buy. lol

milje

Not to mention your transmission is crying for mercy with 37's and 3.73 gears. I have 35's and 3.31 gears but am going with 4.56 as soon as I find a D44 solid for the front, and if my trans goes it's a good excuse for a manual swap.

AZFX4

There's no way you have more lowend with 3.73 and 37" tires.. To big of tires..

Anyways back to OP.

You can fit 37" tires with 6" susp and 3" bl, but not 100% if they will fit into the fender well when stuffed..

If your going to run 35" tires 4.56 would be ideal, and 37" would be 4.88...

Lifted93

I have 3.08s and run 33's and it doesn't seem to bad. I'm looking at some cheap used 35's and i want to find some 4.10's

OUMX117

Lol maybe if they have the 4.8 or the 5.0, and you have the 5.4 all else being equal. Otherwise there's no way in ****, haha. I love my truck, but I have also owned several chevys and they definitely have more power hands down.

ak_cowboy

I used my gears (4.10) for this problem since I want to step up to 35s eventually.
Stock tires (30") --> New tires (35")
Stock 4.10 ------> ~3.50 gears.

The equation to determine new effective ratio is (Old Tire Size/New Tire Size) x Gear Ratio

(30/35)x4.10 = 3.51