so when i lift my truck with a 6inch fabtech and 3 inch body lfit with 37-38 tires and 4.56 or 4.88 gears on my 2005 4X4....what is going to happen to my speed.....highway driving is a biggy....cause if my speed is just gun plumit or im going to be pushing my engine too hard im not going to go this big of a lift..my friends were talking bout this today and i didnt even think bout it at first. also....they were talking bout im going to have to get a locker or something if i do 4.88 gears....are they right or what?

 

No, you don't have to get a locker. In fact, you wouldn't want a locker on a daily driver. Some sort of limited slip, like the OEM setup would be best. As for speed, I'm not sure what you mean. I think you are talking about performance. It should be about the same as stock since your are regearing to compensate for the larger tires. If you are talking about top end speed, your truck's computer limits your top speed to about 98mph. That is not going to change without reprogramming the computer.

 

thanks wandell.....god..your so smart haha...well i meant like..people talk about they are hitting 2000 RPM's at 72 because they did this and what not...i guess performance is what i meant....now...about limited slip...o and do you know what gears my truck has rite now? just a reminder...2005...4x4...i think i have lik 3.73 or something idk...

 

You probably have 3.73's or maybe 4.11's if you have the FX-4 package. Someone has posted a link before to a gearing calculator that allows you to see what gear ratio will give you the same overall gearing as stock with different size tires. Maybe someone will post it again.

 

There are different options available, but most likely you have LS 3.73.
Look on the door jamb, there should be an axle code on there. You'll have to look it up (search for "axle code")

 

thanks....so with a 6inch fabtech and 3 inch body with 37-38 tires think i should go with 4.88 or 4.56

 

Personally, I'd go with 4.88's.

 

thats what i was thinking....yeah i currently have 3.73 i did the axle search...icant wait to do all this....its still going to be another month or 2 before i do this...summer project....but this month im doing an exhaust or trying. so just another opinion ques...should i go with the fabtech 6 or rancho 4 (5.5") with rs9000x's all around

 

I'd go with the 6 inch Fabtech or 6 inch RCD kit.

 

the RCD kit is expensive though...VERY expensive...i can get the fabtech with dirt logics (not the coilovers) for 1800