Yea I know that 4.88s will only work on a 2wd... That's what I have though so no issue there. I thought I heard something about having to modify the carrier or something like that to clear 4.88s?

 

i have 3:55's, if i go with 4:56 front and rear what will my power and mpg be? im 50/50 city highway and average about 100-150 miles a day

 

What size tires do you have? The bigger the tire, the more difference you're going to feel. Adding 4.56's doesnt increase your hp at all...it simply makes it easier for the hp you do have to turn the wheels over and get the giant mass moving. Your mpg will probably increase 1-2 in city and decrease 1-2 on highway, so at 50/50 split you wont gain hardly anything. Keep in mind you can expect to pay about 1600 for parts and install, so its not an inexpensive mod. It was well worth it IMO, but you'll NEVER even come close to "paying it off". Its a performance mod and nothing more.

 

im running 32's and im only getting 12 mpg. it wont even spin the tires at a stand still. im really worried about trying to pull my boat since its 6500 lbs. ive found a company here in san antonio thatll do the front and rear for a grand. i understand it wont increase my hp but it will help me feel it. so far my only mods are cai and a fastman tb and exhaust. next will be gears than programmer or 206 cams.

 

..you have 3.55's and a 4.7...your truck will absolutely love you if you go to 4.56's..

 

whats a master install kit? I didnt get one

 

Shims, crush sleeve, etc. Stuff required to install the gears.

 

Have you tried towing your boat with it? Might want to try first before spending 1,000lbs. The only 4.7 I had was my '05 RCLB 2wd, but it towed 6,500 - 7,500 lbs no problem.