I'm going to swap the rear end on my 03 2500HD ZF-6 Duramax from 3.73 to a 4.10 to tow my monster fifth wheel. Does anyone know a good rear end builder in Southern California. Four Wheel Part does them but I have no idea if they're any good. I know there's a certain voodoo/science to getting these things to work right and last. Anyone done this swap or maybe a 4.30 on a current GM truck with good results

I am considering changing the gears also. I pull a 32 foot gooseneck trailer with a tractor and mower on it. My grosss weight including the truck is around 25.5k. When towing I get about 7mpg. I have been looking at the Kodiaks that have the same engine and tranny but larger gears usually 4.56 or higher. All the post say they get 10-11 mpg towing. I'm hoping the change will help in milage when towing.

Why are you wanting to change, just for mow pulling power?

Four X Dr. in Burbank does a good job at a reasonable price. He is on Victory pl. My buddy had his truck there and never had any trouble. Hoopers use to have a bad rap but this was years ago.

Contact MikeL here. He might be able to help you or point you in the right directions. He's good.

I asked mike when I did my swap. He is a genius when it comes to transmissions but he will refer you to someone who knows more about rear ends. Call randys ring & pinion. They will refer you to a shop in your nearby area. If you have any ?'s on doing it yourself call me. -Chase

http://www.wcdieselperformance.com/

I'l bet that Clyde has done 1 or 2 rearends.

I've done quite a few, but these days I have a guy that does differential work only come out and do them for us. The guy that does them for me makes his living doing gearwork only and he is really good at them. We warranty the parts and labor, but haven't ever had a warranty issue.

I'm running about 70 mph to stay in the sweet spot of the power of my truck which in California is ticket country with a 37' fifth wheel. If I slow it down to 62-65 there's a big difference so I'd like to have the thing spinning on the fat side of 2000 rpms at 62-65 mph. I'm a little leary of going all the way to 4.30 because of the loss of mileage when running bobtail. I've got 265-70-17 take off's from a 06 F350 on it.

I've done quite a few, but these days I have a guy that does differential work only come out and do them for us. The guy that does them for me makes his living doing gearwork only and he is really good at them. We warranty the parts and labor, but haven't ever had a warranty issue.
Hey i lived in elsinore before! Is the lake still green?

Call Bill 818.894.2615. He rebuilt a rear end for my Jeep and did a great job. You can just tell when someone has attention to detail. I'm about to have him do my 2500HD to accomodate 35's

you shouldn't nead new gears w/ 35's. My truck is fine w/ the 3.73's.

If you really want to go to 4.10's give Jim@ Performance Differential a call, He did my 02' and my 05'. All he does is differential's, He's a real stand-up guy and priced very fair. He'll probally tell you you don't need to re-gear.I have 37's on my truck and I was gonna go with 4.56's, he said I would loose the drivability and I would be good with 4.10's.He ws right.
He's in Ontario Ca. I'll try and post his # later.

hey painterjoe what did he charge?