rebel8ball

ok well u didnt give some basic info, like what kind of setup do you have, what kind of rims, is it 2 or 4wd, lifted? slammed? stock? manual or auto (did they put manuals in 04?) everything comes into question when trying to make something perform.

off the top of my head
4 speed (ok 5 speed so you get o/d)(if manual or your willing to go thru the change)
gears
cam will do wonders, just watch the effective rpm range, dont get a cam rated for 4000-7500 when you only run 1200-5500
a stall converter (if suto
shorter tires
smaller or lighter rims (reduces rolling weight)
roller tipped rockers

when u say you have exhaust, do you have hi flow cat, bigger pipes, free flowing muff, headers? the thing is these help on top end, but on low end sometimes engines respond to a little back pressure, or rather the scavenging effects that keep exhaust gasses flowing smoothly and not so much in pulses.

if youre rolling big 20s or 22s or any big heavy rims, and esp if you have all terrains or something heavy for tires, just chaning that will make a decent seat of the pants change...

a hotter spark could help, so could timing adjustments, etc etc etc...anything you can do to add torque.

therewolf

OK, to estimate gears look at your RPMs at 55MPH. Check while cruising on the highway at a constant speed. Keep in mind these are approximations, and not exactly accurate. Tires,lift,transmissions,etc all influence your RPM at that speed. This is only a rough estimate.

1750 RPM=342s

2200 RPM=373s

2500RPM=410s

2850RPM=456s

These are all great gears, depending on your personal needs, and I can't recommend any specific one for everybody.

MnstrRebl

Okay. For all of you who don't know what I'm playin wit. I have a 2004 1500 xcab 6ft bed 4x4 wit a 5.3 auto trans. I have a 4.5 rcd lift running 305/75/16 D.C fc2 on pro comp xterrain rims. I have 2.25-3 custom made true dual exhaust wit flowmaster super 40s. I jus recently installed a k&n intake, td trans throttle bodie spacer, two elc fans, and a superchips powerpaq.

Last weekend on my way back from the local mud runs, I split my eaton 373 gears and carrier in my rearend in pieces. So now I going to put 456 gears all around. But I'm not sure what brand. My mechanic is telling me to go wit eaton again. But all my wheelin buddies are tellin me to either put a detroit or arb air locker in. I'm not really sure what to do yet.

So if anyone has had any experience wit any of those brands or anything close to it, please let me. Or if anyone has any other ideas.

wffokker

I think most of your questions should be answered after reading all the suggestions.
But then il still give you my opinionm, making a 5.3 push a big wind sail ( lift and big tires) with 3.73 gears is probably gone be a bit sluggish, like mentioned before trying to turn big tires and having a lift will make any truck slower, then adding that is has 373 gears doesn't help either. Taking the lift of and going to a smaller set of tires will help big time in it self, or finding a really light set of rims and adding a set of light low pro tires while putting those 456 gears in will also give that thing under the hood some more leverage to get that truck moving.

MnstrRebl

So waht ur basically saying is that wit m lift. i cant really do much to go fast. unless i wanna go lowpro tires and flashy rims??

MDTAHOE

Heads cam and intake set will give you the biggest gain but will also lighten your wallet significantly. You may want to look into a custom Black Bear tune, I have read that it gives you alot of bang your buck. Far better than any other program. It is custom tailored to your driving and what you want to accomplish. It takes in account for the specific mods you have already done