97 F150 4.2 V6
3.55 LS
295x75x16 5" RC lift

ok so ive been researching but havent found exactly what i want.....im looking to regear b/c my truck needs more power....i pulled a 1200lb boat last week and i really noticed it.....but now the BIG question of what ratio to get....i have 3.55s now....i have a 33.3 x 11.72 tire...on a 4.2.....yeah a little underpowered....i can fit 35's and really want to go to thirtyfives to fill the truck out...but i prolly will keep the 33's on for another year...i am almost sure everyones going to tell me 4.56's..and its what i think..i just want some reassurance.....b/c sometimes i feel like its too much gear for my small engine...but then i feel like maybe i need an even lower gear because i have a small engine.....idk...any advice appreciated...thanx

ps...i do mostly back road driving...but some highway...

 

I'd do the 4.56's. It'll be better for backroad driving and especially when you tow man. And definitely since you plan to go to 35's.

 

yeah thats what im thinking....just wonder if its too big for while i have the 33's.......or if 4.56's will be too small for my 4.2 and 35's and 4.88s would be better

 

Honestly, Jake would probably be the best person to ask on this one since he had a lifted 4.2 on 35's.

 

4.56's with an automatic, 4.10's with a manual.

Also, unless they have already been replaced, you need to replace the intake and front cover gaskets. The 97 and early 98 4.2's had bad ones that can cause the engine to hydrolock when they start to leak.

 

intake gasket and front cover gaskets?.....front cover to the intake?....i havent heard of this but ill look into it......

thanx buxton...ill pm jake...

and i have an automatic so i guess 4.56.....what mpg loss/gain could i see.....i guess better around town drivin and worse mpg for highway...but how drastic of a loss/gain?

thanks

 

Front cover (timing cover) and lower intake gaskets are the bad ones.

 

Another vote for 4.56. Been running this set up for 7 years now (see sig).

 

Chris....do you feel like your rpm's are too high on the hiway?....what kind of mpg's are you seeing?....and do you feel like you have "power"?....ill be runnin 35's and just wonder if 4.56 will be low enough with the 4.2....but i feel like a 4.88 would be way to low for it

 

I run 4.88's with 35's on my 5.4.

 

Back when I had the gears installed, I was anticipating running 35" tires, so that's why I chose 4.56 gears. I rarely drive the truck, so it actually still has the 33" BFG AT KO's that I had installed 7 years ago\55k miles ago (and they still look great!). With that being said, I don't regret it at all. My RPM's around 70mph are around 2100/2300 I believe, not too shabby. I do notice that on the rare occasions I get the truck to 85-90 mph (very rare) that rear end is screaming at me a bit. So if you like to "drive it like ya' stole it" more often than not, 4.56 with 33's might be a bit steep for you. I'm completely happy with it. Those gears really help my lil' 4.2 move that heavy truck off the start, around town, and while towing, which is what I mostly use the truck for.

My dad just took the truck from MD to FL and back again this past Feb. He averaged 16mpg. Keep in mind that I have my truck tuned, so my speedometer is calibrated to recognize the changes in tire size and gears. I think that is the key.

 

but of course yours is supercharged, so you feel all the power!

one for 4.56

 

well yeah, but i still was running them before i put the SC on tho.

 

That's quite a hit. With 33's, I betcha it would have gotten closer to 20 with 4.10's.

 

yeah i think for the short time that ill drive it with 33's and 4.56's (less than a year) it would be ok....especially because i never drive it hard ..or like i stole it.....but im deff going to 35's so i just wonder if 4.88's would be better for my little 4.2....or if like glc said...4.10s would give me the better mileage....