So first off I know this is a stupid question and I know I can search it but just wanna get some feedback from y'all so here we go
1. What's gears are in my truck now I got a f150 4.9l EFI 4x4 with the 8.8 in the rear I can't read the tag on the diff cause it beyond rusted and coated in god only knows what
2. I plan on lifted it and putting 37's up under it and wanna know the best gear ratio I should run for them to get alright gas mileage cause I know I ain't gonna get the best and good to go wheeling cause it my daily and my toy
Thanks and again I'm sorry I know I could search all this but I just wanna get some feedback and thoughts from y'all
3.55's with 37's would be TERRIBLE. But thats not all. The TTB front axle simply cannot handle 37's. Don't let anyone tell you otherwise. I had 35's on mine and it ate balljoints, universals and could not stay aligned for more than 500 miles. And with 37's, there shouldn't be any discussion of fuel mileage other than it will suck. You are going to have to solid axle swap with a 6" lift and 4.56, possibly 4.88, gears as well as simply putting fuel economy out of your mind to have a reliable offroad toy that could be driven when your done wheeling. Your best bet for an offroad toy with 37's is a Dana 60, Sterling 10.25 swap, which will likely require a donor truck.
Ok it is a 19 the bottom of the 9 isn't all the way there sorry bout that and thanks all at the sometime hahaha so I got 3.55 right now then
Anything larger than a 31" tire will suck with 3.55 gears. I just bought my '94 a few weeks ago and it has 3.55's and had 33" tires on it when I got it and even the 33's were too big for that ratio. Really, with these TTB front setups, if you want to go any bigger than stock, you might as well do a solid axle swap because otherwise you will eat ball-joints and bushings like a fat kid eats cake...
Anything larger than a 31" tire will suck with 3.55 gears.
"Suck" is not a very quantifiable term. What sucks for some people might be fine for others. Also engine and trans both make a huge difference.
I had 3.55s and 33" tires on my '95 F-150 with a 351 and E4OD. That combo worked great for me. I hauled 11,000 lb loads (total including the weight of the truck) in the Rockies with that setup and was perfectly satisfied with it. It certainly wasn't as fast as it would have been with 4.10s, or a 460. But for me that was the right setup.