i believe my current ones are 3.73?

You dont have to. Im running 37s with stock 3.73s. It will help with performance and mileage though

No. You do not have to change your gears. I'd recommend (along with many others) that you change them to keep the performance of the truck and longevity of the tranny.. but It's not mandatory.

You can find out what gears you have by looking out the tag on the rear diff. I have it circled in this pic. Mine says L55... meaning it originally had a Limited slip with 3.55 gears. If it says L73.. you have limited slip with 3.73 gears.

You don't have to, but I have noticed a big difference in the power department since I had my 6" lift and 35's installed. Just waiting for the performance shop to call me to deliver my truck and have my 4.56 gears installed.

whats the cost of the 4.56s ??

What gears do you guys recommend for 37" tires? I was thinking of getting a set of 4.10, or 4.56 if I ever get around to lifting mine. I don't want it to be a real gutless pig, but I don't want to be stuck going 90KM/H reved right out on the highway cause my truck is geared low either.

I've got 4.88s with no problems. I don't think you'll have a problem getting up to speeds, remember you'll be on 37s. Most 37" tires arn't speed rated past 100 mph and the 4.88s will allow you "technically" to go much further than that. However the aerodynamics rival a speeding brick so wind resistance is actually going to cut you short rather than the gears.

So really even with a set of 4.88's I will be able to roll faster then the speed limits on the highway without being flat out? How does your truck take off and accelerate with the 4.88s? Is it comparable to stock gears and tires? I was looking at your truck earlier today actually..I must have drooled for about half an hour, I want a similar setup for mine.

I actually think it has a little more power now than it did stock. I'm running 2100 rpms at 70 mph which is pretty damn close to stock. I think stock is 2000 rpms at 70 mph but I could be wrong. Thanks for the compliments though!

Thanks, that answered any questions I had about gears.

As much as I hate to HI-Jack, you have any suggestions for a guy thinking of getting an 8" Rize lift kit, a set of 37/13.50R20 Wheels and Tires and 4.88 gears? Anything you would have gotten, or done different?

u plan on 37's on your hd?

whats the price of gears and where do i buy them?...also if i just do 35's with no suspension lift ( i already have a leveling kit) do i need gears?

35's should clear with a leveling kit, I've seen a few trucks done like that. Theres something about the wheels though, it doesn't work with aftermarket wheels, something like that, I don't remember exactly what. But it should clear. I don't know if I would even bother with gears if your getting 35" tires, run it stock and see how it is, if you find its gutless get a set of gears.

Never fails, everytime I say that somebody pipes up haha. Yeah, I'm looking at lifting it and running 37's. I wouldn't be the first, I've seen atleast 4 HDs done up with lifts and bigger tires.

i havent seen on but that must look sick

I think it does.