I have read a lot of posts that discuss gears & lifts. If I go from 33's to 35's on my 2001 Flareside 4X4 with the 5.4 L V-8 do I need to change my gears? A lift salesman told me to wait to see if it is necessary. I am concerned that my speedo will not function properly or that the engine performance will be adversely effected. If I need to change do I need to change front and rear or just the rear? If I am going to spend most of the time on the road and occasionally on the highway does that make a difference. My truck is going to be for show and tow primarily. What gear ratio do you recommend? Where should I buy the gears? Is a certain manufacturer recommended over others or is there only one to choose from? Any advice will be greatly appreciated. Thanks. Steve

 

Depending on what gears you have stock, it can raise your gas mileage a good bit and give you a lot more power when you re gear. If you have 3.73s stock, then 35s will be ok, you will notice a little power and mpg loss, but not much. If you have 3.55s, then it is a good idea to regear. Not necessary, but you will loose a good bit of power and mpg with 3.55s and 35s. A good ratio to go with on 35s is 4.56, and some good brands are Yukon, Motive, and G2 gears.

 

I have 4.56s and 35s, and it's the perfect combo. Definite power gain and mpg in the city went up. I think highway mpg stayed about the same. You HAVE to regear the front and rear with the same ratio. Your speedometer will be about 10mph fast with 4.56s and 35s, or at least mine is. That can be corrected with a tuner though. You'll be happy with 4.56s and 35s for towing. I towed about a 10,000lb tractor with mine and it did really good

 

Since you said you do mostly city driving, you will love 4.56s. Acceleration will be effortless. I rarely ever get above 2200 rpms just daily driving

 

I will check the window sticker and documents that were provided to me by the original owner to see what gears I have currently. Is there any other way to check what gears I have? I would love to learn more about gears and performance. I also need to learn about tuners so I can make sure that my speedo is accurate.

 

You have to do front and rear gears if you want to use the 4WD

 

The sticker on the driver's door that has the tire information and stuff on it will have an axle code on it too. See what that is then google it to find out what gears you have now. The window sticker that came with the truck should also tell you what your gear ratio is, if not, your axle code will. And if you regear, you have to get the same gears in the front and rear

 

The factory sticker says I have "3.55 ratio limited slip axle". The truck originally came with 265/70R17 ATs. When I bought the truck it came with Nitto Terra Grapplers that are 285/75R16. The truck has good pickup and plenty of power. Not sure what my fuel mileage is. How will 33's look with a 6" Fabtech lift? I had planned to replace the tires with 35's but I do not want to loose performance or spend another grand on gears unless it really makes sense to do so. Heck I may just replace the tires and leave the suspension alone. The truck looks good. Maybe a little squatty. I would post pictures if I could figure out how to get them from my iPhone to this site. What do you guys think? SMM

 

33s will look really small with a 6" lift. I had the same gears as you stock. You will lose a good bit of power with 35s and those gears, but 4.56s more than make up for it. Here's my truck with 35x12.50 R17 Nitto Mud Grapplers and a 6" Fabtech lift:

 

You also have to take into account what you tow. My old Screw had a 5.4 engine, 3.55 gears and 35's and my performance was ok. But I only towed a 6x10 utility trailor and two dirt bikes.

 

Mossyoak-Great looking truck! Those are some big a-- tires! The salesman at 4WP said the truck would look silly with a 6" fabtech lift and 33's. He thought new gears would cost as much as $1,500.00. He suggested I try the original gears with 35's and then re-gear later, if necessary. I would hate to lose performance and mileage. I'm not sure if I can replace the gears myself. I do have a couple friends that could do it reasonably for me.
Wandell-I tow a 5X10 cargo trailer or a 15' Whaler. Thanks to both!!

 

New gears will cost close to $1500 unless you know somebody that can give you a good deal, which it sounds like you do. It won't hurt to try 3.55s and 35s. You will lose performance and city mileage for sure but you may not mind it enough to justify the cost of regearing. Doing the gears yourself would be pretty difficult unless you really know what you're doing. I put my lift on, but I didn't try the gears

 

I will let the pros do the gears. I am still debating on wether or not I want to attempt to install a lift kit. Time and money are both in short supply! I am gathering parts a little at a time so that one day I can put it all together. I need to replace my tires soon so that is why I am researching lifts, gears, tires, etc. This website is a great resource. BTW, I drove the truck tonight. It already has 33's on it and it has great performance as far as I am concerned. The 35's are really only 1.8 inches bigger. 33's are really 32.8" & 35's are really 34.6" according to my calculations and the Wallace Racing Tire Calculator. My daughter is driving the truck now why I look for a economical and safe car for her. Once that is accomplished I will drive my truck on weekends primarily. I guess I can always have new gears put in later if I am not happy with performance.

 

it also depends on the tranny. i had a 90 f150 with a c6 trans. we had 35/12.5s on it with stock 3.55 gears. no acceleration. then again its was a 5.0, they just have no *****, sorry to those people who own 5.0s. but a friend of mine had 3.55s in his 97-03 f150 4.6. that was pushing it for his 4r70w trans. the c6 could take it cuz theyre so tough. but keep in mind if you leave stock gears and go big, itll put a lot of stress on the trans cuz itll keep shifting in and out of overdrive. my 5.0 would shift out of OD if ya went up a small hill, and the mph's plummeted. and gas mileage sucked. would burn a quarter tank in bout 20 miles. it all depends on how big youre going. 33s and 3.55s are ok. 4.10s would help, but its up to you. 35s, go with 4.56s. great combo. regearing is when ya need to put your city mpg back to normal and for extra torque for towing. good luck to ya buddy.

 

I'm convinced I will have to re-gear if I go to 35's. I'm going to figure out what that will cost me and then decide if I want to lift and go to 35's. I have an automatic transmission. Not sure which one. My engine is the 5.4 l V-8. Lots of decisions! SMM