Join Date: Apr 2006
Thanked 29 Times in 24 Posts
With 36" tires a gear swap to 4.30's will give you a lot more power out of the hole and take a lot of strain off the transmission. 4.10's will get you close to original performance, but the stock 3.73's are too tall for my taste even with stock tires especially if you plan to tow over 8,000# frequently. You mileage is going to suffer from the tires regardless of which gear you choose, the choice is to save 1/2mpg or pay for a transmission rebuild sooner (especially if you mod the engine with the stock gears and 36's)
I'd concentrate on the transmission first, a VB
swap or Sonnex/Tricummulator kit will help shifting quite a bit, after that a tranny cooler from a 6.0L truck will keep it from overheating, I'd also recommend replacing the 3/8" steel lines with 1/2" rubber hose front to back (the 6.0's have 1/2" steel and the cooler has 1/2" barbs for hose) Lose the radiator cooler altogether (it will be a restriction anyway) and the bypass valve assembly on the side of the transmission (where the banjo bolts hold the short tube in place) install pipe threaded barb fittings in the holes to fit the hose (you'll need one 90* and one 45*, also, one is 1/2MPT and one is 3/8MPT) I used the 3/8MTP-45* in the front hole and routed the hose behind the dipstick tube, the 1/2MPT-90* goes in the back hole.
The bypass is ONLY in case your factory cooler plugs COMPLETELY up, when you see the size of the 6.0 cooler, you'll see that's totally impossible (the 6.0 tranny's don't have the bypass)
07-6.0 4X4 CC Lariat Tow Boss w/36,000 trouble free miles.
CCV-Zoodad-Harpooned, cat delete, otherwise