I have an 05 stx reg cab with the 4.6. I'm going to be installing a leveling kit and some 17x9 rims with 33s mounted on them. Will 4.10 gears be a good choice to keep the truck from bogging and losing a ton of power? What can I expect for performance decrease and gas mileage? I did a search but couldn't find what I wanted to hear.

 

4.10's would be a good choice. How much you power and milage are affected depends on what you have stock. What I'm saying is if your truck came with 32's, you won't notice as much of a difference as you would if you truck came with a really small tire.

 

I've got a 4.2L 4x2. Stock it got about 14-16 mpg. Now it's lifted 12" and running 37's. I regeared to 4.56's and I get 12-15.5 mpg. Not much of a loss. I'm putting e-fans on next month which should bump up the mpg by 1-2 mpg.

 

Thanks for the replies. I get about 15mpg now all city driving. Truck is a 4x2 and came with 30" tires. I know the mpg will go down, I just hope it's not drastic. I'm either getting the BFG AT 285-70-17 or Nitto grappler 295-70-17.

 

Hey 05STX, I have a 4.6L XL and I'm going be putting on 17s and 33 inch tires as well. What wheels and tires are you looking at? As far as gearing goes, I've been reading that since we have 4x2 trucks we can run 4.30 gears since we don't need a matched set. 4.10s put the truck back to where it was stock with the 3.55 gears and 30's, but the increased weight of the tires makes me want to go for the 4.30s to make sure I don't lose power. I also do a lot of around town driving so I need to make it easy on the truck off the line.

 

Yeah I thought about 4.30s as well but in 10 months when my house is built, I'll be driving about 60-70 hwy miles to work each way. If I was staying close I'd definately do the 4.30s. I only have to make the drive twice a week but I don't want to pay anymore then I have to for gas. What would 4.30s with 33s give you for a gear ratio anyways? As for rims, probably these. http://cgi.ebay.com/ebaymotors/ws/eB...tem=7986211916

I know they have been done on alot of trucks but I like em.

 

Wow, 400 bucks for all 4. I need to do more shopping around. I thought all the 17s available for my truck were at least 200 bucks a piece!

 

Yeah man. I emailed that seller and those are about 475 shipped. Give or take a couple bucks.

 

How much are new gears? Is it a do it y ourself kinda job at home in the garage?



-Chris

 

No, installing differential gears is not a project for a do-it-yourselfer or even the "average" mechanic. The gears have to be set to very precise tolerances or they will make a ton of noise and/or wear out quickly.

 

Wandell, I see many times when people begin talking about what it takes to work on their differentials that you often times discourage this type of venture for the "average Joe" and understandably so, it is truly not a job for the novice. My question is, however, how much difference is there between the 8.8 and/or the 9.75 and the old 9 inchers as far as the specificity of tolerances. I have rebuilt some old nine inchers as well as numerous GM ten and twelve bolt diffs. and I just wondered what the difference would be, if any, in doing this type of work on the newer diffs. I haven't had any trouble from mine to date and hopefully never will, however, if something were to happen I would do the work myself. Any input would be appreciated.

 

thanks wandell, can you give me a estimate on how much regearing cost ( parts + labor?)

-Chris

 

your probably looking at $167 Yukon gears (That was for my 8.8 to4:56 gears and 86.58 for a master rebuild kit. Then installation would be around $340. You should check out Randys Ring and Pinion. They are a good site and you can call up and talk to them.. They are very helpful.