I lifted my 96 f150 4wd 300I 6cyl. I put 33" mud tires on it and am wondering what i should do first change my gear ration and if i do what to i was thinking 3.73s because i have 3.55s right now and i dont want to lose to much more on the mpg and i wheeled it the last couple weekends and my low and 4low combo seem to still be a low enough ratio. Or should i get a locking setup for the rear first because i did get stucj between a rock and a stump last weekend where if i had a locker id have easily made it out and if that setup use a detroit or a tracklock, keep in mind this is my daily driver! Thanks a bunch

 

3.55's are good enough for a I6, considering that it was available with 2.73's. (Not a typo - that really is a "2"). You have stump pulling low end torque and 4lo, that's all you need and do you really want higher RPM's and worse gas mileage on the road?

Going from 3.55 to 3.73 is hardly worth it - especially considering you have 2 axles to do. I'd keep the existing gears and just put some kind of posi or locker in the rear.

 

Going from a 3.55 to a 3.73 isn't worth the time or money. You MIGHT notice a tad more "oomph" off the stoplight, but you'll be running a couple hundred RPM higher all the time with taller gears. 4lo is already giving you a 2.69:1 ratio boost for off-roading, so another .18 turns of the driveshaft really won't benefit you much.

For a daily driver, you want all the MPG help you can get.


I'd go with either a good posi or a locker rear end and skip the gear swap. Both wheels spinning will do a lot more for you in the mud then a little more torque.

 

The stock tires are 29"

With 33" tires and 3.55s, you're turning roughly the same RPM as stock tires and 3.08s.

To get the RPM equivalent of 29" tires and 3.55s with your 33s would require 4.11s.

 

how much of a mpg difference are 4.11s going to make is the thing im worried about.

 

4.11's will kill your highway mileage. Shouldn't affect around town though.

You really want to spend the big bucks for regearing both axles? You could pull stumps in 4lo with 2.73's and your tires - but you would probably never use overdrive on the highway.

 

Since when does regearing for larger tires kill any sort of MPG? If I was going to spend the time and money on this truck, I would do a LS in the rear with 4.10s and an Aussie Locker in the front with 4.10s. But why waste the time.

 

We are talking about an I6 here, not a high revving V8.

 

why lock the front i'd rather lock the rear and ls the front if anything. well most of my miles are highway miles so i need the mileage there

 

Keep the 3.55's. That old I6 will be barely above idle in overdrive putting out a bunch of torque.

 

thanks guys i think i will lock the rear for now and wait until i get a bike to do anything else to it. Once i have my bike ill be able to really turn the truck into a wheeler

 

With 33s and 3.55s you'll turn about 2250 RPM at 60 in direct.
If you have a manual tranny, thats 1800 at 60 in 5th but with an automatic it's only about 1575 in 4th.

If you ever drive on ice or snow, you'll have a steeper learning curve with a locker than with a limited slip.

 

Because a LS in the rear is better for road manners and when it is in 4WD youll want both front wheels pulling.

 

I don't think I'd want a front locker without manual hubs.

 

i have manual hubs but i can tell you what i definitely do not have the money to lock the front and back