TORREY1150

Got a 97 F150 3 door super cab with 4.6 added a zone 6" lift running 35-12.50-R16. Looking to re-gear to regain power, mileage and ease strain on tranny, any recommendations?

BEHR91

I'm new to forum but am a avid Jeeper and always regear my rigs, for 35s I would run a minimum of 4.56 or 4.88 . I always go with deepest gear set recommended for size of tires I want to run.

tareed94

Yikes that's really high. I was going to recommend 3.73 or at the most 4.10. In these trucks (granted I'm not sure with the 4.6) people go with 4.56 when they're in 37" plus. Which a lot of it depends on what your goal is. Being a jeeper you probably are/were crawling a lot?

OP, what's your stock gearing?

BEHR91

I have stock 3.73 and they would not roll a 35 very effectively. 4.88 may be too steep but 4.6 need some rpm if only you could get 4.30 for the front diff and not just the rear

tareed94

On the jeep? What's the power difference though? Not trying to be THAT guy, just asking questions for my benefit as well.

I had 3.73's in my 5.4L '07 with 35's, it definitely took a hit, but after I tuned it it was fine. Ran around 2200 rpm on the highway. Which that's a totally different scenario than OP. Now, my '16 with the 5.0 has 3.31's and these 33's hurt my gas mileage a significant amount (18-20mpg highway, now 15mpg highway)

BEHR91

[QUOTE=tareed94;5434959]On the jeep? What's the power difference though? Not trying to be THAT guy, just asking questions for my benefit as well.

I had 3.73's in my 5.4L '07 with 35's, it definitely took a hit, but after I tuned it it was fine. Ran around 2200 rpm on the highway. Which that's a totally different scenario than OP. Now, my '16 with the 5.0 has 3.31's and these 33's hurt my gas mileage a significant amount (18-20mpg highway, now 15mpg highway)[/QUO


In my 2015 which makes 285hp 260ft lbs most of which is available 1500 rpms to 3000 needed 4.10 gears to run good that with a 5 speed auto much better gear spread and a lighter rig. I probably went to far with 4.88s but with the 4 speed you need more gearing I think 4.56 gears with a 35 basically equates to 3.73 with factory tires. In my older jeeps I go really low like 5.13 and such for rock crawling. Now I'm not saying the 5.4 wont roll 35s with 3.73s but might as well get your factory power back if your going to make the investment and regear , IMHO

PerryB

To me, 4.56 no question. And a Truetrac.

SteveLord

4.56 at least.

Havyek

I may have missed it but did OP state what the purpose of his rig is?

I'm also a Jeeper, run 410s on 35s, wish I would have gone to 456s.
410s on 35s ended up being a slightly lower than stock ratio (but not by much). I would rather the engine be revving a bit higher and putting out more power, more easily with the 456s.

If OP is running a daily driver with little/no off-roading I'd go with 410s or 456s, if it's a DD rig that offroads, I'd go with 488s.

I'd rather the engine be revving higher than losing any gears on the highway. Would also rather buy the slightly taller gears than spend the money on re-gearing just to have to spend more money on tuning.

Eric Kleven

Your 4.6 is a short-stroke 5.4, you could go two gears slower on your 4.6 and be about the same as a 5.4 as far as piston velocity goes. 4.56 wouldn't hurt that engine at all.

Put it this way: with stock tires, a 5.4 with 3.55 would be the same swept volume/power/fuel burn as a 4.6 with 4.10's.

two sizes.

go.