i figured im better off posting here bc we have the same chassis....

I have 3.73's in my truck and with the 35's i dont think thats too great... i want at least 4.10's maybe 4.56's but what would the cheapest way of doing this be? anyone wanna trade axles also if i bought gears (which arent cheap) could i reuse my factory lsd..?

 

You should have made this a poll

 

cheapest would probly be to find a wrecked truck and get the rear with the 4.10s, other than that swapping gears is probly cheapest [sm=smiley13.gif]

 

y? its multiple questions...

 

you have got to be carefull. . .you have a 10.5 axel where as the HD's have the 11.5 axel.

since you went to 35's, 4.10's would put you very close to stock on the speedo.

however with that hemi you got and 35's, you may actualy benifit more with 4.65's.

 

wait you have an 11.5? i thought that was dually's...

 

nope. . .gasser 2500's have the AAM 10.5 axel. . .all 2/3500HD's have the 11.5 axel. now in 03 there was a run of the SO and cali output engines that ran the 10.5 axel, however once the torque figures went up the 10.5 couldnt handle the stress.

 

Go with the 4.56's, you'll be much happier with them.

It never pays off to just go one gear size....too much money, too little benefit.

Example:

On my last truck I went from 31.5" stock tires to 36" SSR's. I was on the fence of going to 4.56's or 4.88's. I thought the 4.88's would be too much and went with 4.56's. Man did I kick myself later.

With that Hemi, you have so much RPM to work with, it won't hurt to go 4.56's. Besides, your butt will thank you for it.

Look at it like this, every step up (numerically) in gears sets will net you about 200 - 250 RPM's difference at highway speed.

What you REALLY wanna look at it where your torque curve starts to flatten out and shoot for that RPM range on the highway.

Remember, with a gasser low RPM's do not necessarilly equate to better fuel mileage. If you are. lugging the engine in the low RPM's, then you are still dumping in fuel you're jsut not going anywhere.

My advice, after doing a few gear swaps, is 35's and 4.56's are the ticket for a daily driver. If it's more off-road oriented then 4.88's or even 5.13's aren't out of the question

 

does the gear swap go for the cummins too? or just gassers? i remember reading old posts before i went up on the tire size and people said stick with the 3.73 with 35s. would it be more beneficial (increased sense of power, better mileage, etc)? eventually i plan to go up to 37s. are there more people here running their 35s with 4.10? whats my best bet? sorry if i'm hijacking...

 

First thing with gears....If you aren't going up at least 2 sizes, don't bother; you'll never even notice.....except your much lighter wallet.

If you are gonna change gears, a good rule of thumb is for every 2" of tire size, go up a gear size.

Second thing with gears...Selecting gears for fuels economy is like getting a diet coke with a whopper meal...It will NEVER pay off.

When selecting gears, be reasonable in what your TRUE useage is gonna be. Once you've established that, look at the speeds you normally run at and target the part of the torque curve where it flattens out. This is where you want to run as it gives you good power and keeps your tranny from hunting like crazy. Too far either way and 1 - you'll be pegging the RPM's or 2 - you'll be too low in the RPM range, lugging the motor and getting crap mileage and power.

A reasonable estimate for a gear swap, per axle.

Gear set - $200
Install kit - $100 - $200 (depending on the level of the kit)
New differential - (not necessary, but while you're at get a locker or good LSD) $400 - $1000
Labor - $300 - $500 per axle

So, at a bare minimum, on a 2wd truck with no new differential you are looking at between $600 - 900 for a gear swap. Double that to $1200 - 1800 for a 4wd.

This IS NOT a beginner setup. If you've never done gears, get someone to do it. They are so easy to screw up it's not even funny.