4:56 axles or just towing in third gear....????

To start, I've got a k2500 suburban w/7.4, 4l80e. I've had 33's on it for years (65k miles or so) w/3.73 gears runs little under 2000rpm @70 in OD). Towing (4-6K pounds very rarely, no probs with overdrive, unless I'm towing my 30' camper trailer), daily driver, family road trip stuff etc. I do not race my truck, I do not hot rod it around, I don't really gaf about fuel. With the 4" lift I've decided to go with 17" wheels with 35's. Now that I've decided to change wheels and tires I thought it a good idea to do 4.56 gears. I KNOW that would be ideal, but I'm curious, so I did the calculator thing. It seems I can cruise at 70 in third maintaining 2100 rpm with 35's keeping my 3.73's, 4th would be 1560rpm (really low rpm I think). I know all around 4.56 would be easier on the tranny, and more fun to drive. What's the difference? Tow in third gear and save a S***t ton of money on a re-gear or is it really worth it to re-gear axles all together? Best quote I got for 4x4 re-gear, no tune, is around 5k. That blew my mind. I can buy new trans for that much when I "supposedly" roast this one with my 3.73's. By the way, my 44 gal fuel tank wieghs over 300 pounds full, I have 4-8 people varying in weight and age in my truck often with all their crap and feel no difference while driving. How the hell does two inches of tire height and the additional weight of the tire etc. merit a re gear?

The regear will effect all gears not just the gear you tow in...so your overall driving experience will be better, the 454 will be happier too.

Regearing also takes some of the load off your trans not just because of the reduction but because it wouldn't be constantly kicking in and out of OD.

I had 3.42 and 33s on my truck for a long time and it would constantly hunt for gears on even the slightest uphill road.

Agreed, regear. My '95 2500 got 315/75's and 4.88's. The cost is well worth it to keep the 5.7 in the power band in every gear.

Guess that seals the deal. Thanks for getting back to me. I ultimately agree. I'm going with the 4.56 gears. Since I've posted I've been scouring for options. I've decided to buy a 14 bolt rear end with 4.56 gears and the disk brake conversion installed from zumbrota reman. If I'm reading this correctly, it's going to be around 2k for the rear, and $1500 for the front. I think its a semi float vs my full float, didn't see any reason for that to be an issue. Saves me from doing it myself (never done one before, and don't plan on doing one in the future), saves me from a mechanic, and I can keep my old stuff. I plan on driving this truck forever, thanks again.

lukeapre said:

I think its a semi float vs my full float, didn't see any reason for that to be an issue.

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Just confirm your log bolt patterns, normally a SF is 6 lug and a FF is 8.

PlayingWithTBI said:

Just confirm your log bolt patterns, normally a SF is 6 lug and a FF is 8.

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Actually the 14 bolt semi floating axle is available in 8 lug. Had one in the '90 R2500 square body Burb, seen the 400 version in the yards. FF is 10.5" ring gear, SF is 9.5" ring gear though.

You can always throw some smaller tires on for towing.

Look for a truck that came factory with 4.56s. 100% bolt in. What I plan on doing with mine.

b454rat said:

Look for a truck that came factory with 4.56s. 100% bolt in. What I plan on doing with mine.

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That's basically what I'm going for, except add disc brakes.

HotWheelsBurban said:

Actually the 14 bolt semi floating axle is available in 8 lug. Had one in the '90 R2500 square body Burb, seen the 400 version in the yards. FF is 10.5" ring gear, SF is 9.5" ring gear though.

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Yup you're right. Some have 8 lug, but I found a 14 bolt ff axle w/4.56 from hillbilly wizard. I think. I visited so many sites I can't differentiate anymore.