im about to put an rcd 6" suspension lift on my '04 fx4 supercrew (5.4), with some 35" mud grapplers and 20" wheels. Will my truck still have enough power. i plan to later put a new exhaust and air intake.

 

Unless you regear, no.

 

Negative.

 

Who says?

Personally, I've had a 2004 F-150 on 35s with a 6" lift with stock gears. Whats enough power to you? Honestly, do you plan on hot-rodding the truck or just driving it normal? Yes, gears would be a great help to the power and reliability department. But, grab yourself a tuner and it should hold you off for a while. I could still spin my 35s off the line with just exhaust, a K&N drop-in and the Edge.

 

U will loose power, and yes gears will help. It all depends on what u plain on useing the truck 4. If u r gpoing to tow anything I say u need to get gears frist. I would not go to long of a time with out getting gears anyways so u don't put your engine under to much strain.

 

Also, what gears your truck has now are a factor. If you have 4.10's, you will probably be fine with 35's.

 

Were 4.10's even available on the '04 FX4? I don't think they were. He most likely has 3.73's, at least I hope so, because 3.55's are lame!!

 

just a question cause dont know much bout trucks but very intrested i just got a 01' 4x4 screw 5.4 v8 and how am i suppose to know what gears im running. and couple my buds have ran 35's without regearing for a while just depends what ur looking for

 

It may say on the sticker inside your driver side door. My '04 even had a sticker inside the fuel door that read the tire size and some other stuff I forgot now.

If all else fails, your local dealer, using your VIN or codes inside the glove box, may be able to tell you - perhaps even for free, which would be mighty white of them.

 

Get the axle code off of your door jamb sticker, or for even faster results, get down on your hands and knees and crawl under the truck and read the axle tag. Mine says 3L55, which tells me that I have 3.55 gears with a limited slip. If there is no L, then no limited slip.

 

thanx for all the info. but got 1 more question. I found out that my truck has 3.73 lsd gears and was wondering what i should upgrade to (4.56 or 4.88 or what)? I dont do any hot rodding or towing. I very rarely go off-roading. just normal every day driving.

 

If you have stock 3.73 gears and 31" tires then going up to a 35" tire would leave you with the equivelant of 3.27 gears.....crap in a truck. changing to 4.10 would get you back pretty close, but I would go for 4.56 gears to help offset the heavier rolling mass of the new tires and the loss of aerodynamics your going to have.

 

My tires are 34" and I have no need to regear from the stock 3.73's. The bigest thing I have hauled is a 700 lb. ATV, though. There is a slight lag with it on there, but not too bad.

With 13" wide 35's you may need/want a regear; that's a lot of tire. Try it for a while and make the call.

 

Dude I would freaking go for it. I drive my truck mainly on the street and drive slow as is so I don't mind the power loss in my truck.