I noticed this thread and couldn't help but to look. I have a 2000 F150 4X4 that I have lifted and installed larger tires on and I just thought I might post some of the issues I ran into along the way as I noted that some of you were asking in this thread. These held true for my individual truck and may or may not hold true for everyone. I installed a 6 inch Fabtech suspension lift combined with a 2 inch body lift. The installation instructions were pretty much straightforward for both kits. Lifting the front of these newer IFS F 150's gets pretty involved, though. If this is the first time you have lifted one of these trucks(as it was for me), 12-16 (full weekend) hours installing the suspension lift can be expected. I have heard of experienced shops doing these in about 6 hours, but for the average person better double that. I wound up having to shorten my tie rod ends by about 1/4 inch to get enough adjustment to have the front end properly aligned. Not all trucks will need this mod from what I understand. I installed 37/12.50/R17 BFG Mud Terrains on this truck on 17 X 9.75 inch Centerline rims with a 4.5 backspace(I think that this is the stock backspace). Some sources informed me that the 9.75 wide wheel could cause a vibration problem but I have not noticed any vibration on my daily driver(I put around 80 miles a day on it) and have around 60000 miles since I lifted mine. These tires do not rub (not on my truck anyway)with the lift combo used if the bumper is lifted correctly to match the body lines using the brackets supplied with most body lift kits and setting the torsion bars at the stock setting when adjusting the bars. I regeared my front and rear diff's using 4.56 gear ratios. Because of drivability issues I would consider lower gears in any of these trucks running tires bigger than around 33-34" Some people might argue this but these gears helped me to maintain all of my truck's power and still get around 14.5 MPG out of the 5.4, which is pretty good for a lifted ride of my height if you ask me. The last issue that I ran into was the speedo calibration. My truck had 3.55 gears and 265/70/17 tires stock. The 37 inch tires and 4.56 gears gave me fits. The stock computer would accept a max tire size of 34" and would not accept my numbers. What I wound up doing was mathematically calculating the error and picking a dummy tire size and gear ratio that would give me the right percentage of correction for the speedo and ABS. For the tire/gear combo I chose I wound up entering around a 30 inch tall tire(if memory serves me correctly) and a 3.73 axle ratio in place of the stock 31.6 tire height and 3.55 gears as the parameters in my vehicle's computer. Everything seems to work fine now and my speedo is within 1 mph of my GPS riding on my dash. I know that this info is a little beyond the scope of this thread but I noticed that several of you were considering lifting your trucks and I thought I'd share my experience with mine and some of the things I ran into. Sorry about the long post.