Stock 3.73 or 3/4 ton 4.10 axles

[Tony454]

I've got some options with parts I have in the barn. Wondering what others think about running half ton with 3.73 gears or a 44 front and 14 BFF rear with 4.10. The only real reason I can think to do a swap is just so I can say "hey look at my 3/4 ton axles". Never going to do any serious off roaring or towing. What have you guys done for axles and why.

Thanks
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[jaros44sr]

JMHO! But, i think it all depends on what size tires you are going to use.....

35s and above might snap an axle on 1/2 ton, 33s seems to be the right combo w/3.73. 4.10s would give you better throttle response off the line. Dont forget, youll need bigger brakes with bigger tires, or go hydro. 15" wheels are hard to fit with one ton brakes

[Tony454]

Honestly I'm planning to do a four inch lift and 33's. I'm thinking the k5 will have better highway manners with the 3.73's. and also planning to run an o/d trans so getting the rpms down a little more for that would be good. Thanks for the input, it reaffirmed what I was already kinda leaning towards.
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[Special-Ed]

4:10 is a gas suck! i have a 4.10 on my suburban... every fill up i wish it was a 3.73

at 90 mph i can watch the gauge move at 100mph i bet im getting 7 miles to the gallon

at 70 with cruise on flat with wind at my back i can get 17 maybe 18 mpg

but in order to tow my boat i needed the 4.10...

[Mike C]

What transmission and what size tires? Honestly, once you do the 33's and the 4" lift you'll decide they are too small for that much lift IMO and you'll want 35's. And if you stay with the 3.73 you'll want more gear.

With an auto I would do 3.73 if you are going to drive it much on the highway (converter slip) but with a manual, I would do 4.10's on the 35's.

Obviously you need to make these decisions before you buy wheels and tires. If you decide to stay with the 1/2 ton axles in the short run, at least move up to 16" wheels. Then if you want to go to the 8 lug axles before the tires are worn out you can at least use them.

I own a whole boat load of 15" off-road tires that are too old for using on the highway and won't fit on any of the off-road only vehicles!

[BOHICA]

Originally Posted by Tony454

I've got some options with parts I have in the barn. Wondering what others think about running half ton with 3.73 gears or a 44 front and 14 BFF rear with 4.10. The only real reason I can think to do a swap is just so I can say "hey look at my 3/4 ton axles". Never going to do any serious off roaring or towing. What have you guys done for axles and why.

Thanks
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Doesn't make much sense to put a 14 bolt FF in the rear and keep a 44 up front. Either upgrade your front axle to a 60 or stick with half ton parts.
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[Tony454]

Like I said before these are just parts I have on pallets in the barn. Not really looking to buy a Dana 60 just thought since I had the axles already it might be worth it to use them. But I'm leaning towards staying with half tons right now.
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[Mike C]

Originally Posted by BOHICA

Doesn't make much sense to put a 14 bolt FF in the rear and keep a 44 up front. Either upgrade your front axle to a 60 or stick with half ton parts.
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I disagree with this. Having broken seven 12 bolts in seven different ways I see lots of merit in moving up to the 14 bolt. I have a semi-float 14 in my Jimmy right now with the 8 lug 44 front. You don't need a Dana 60 in order to off-road even hardcore trails with a Dana 44 just running 35" tires.

If I had upgraded mine when I broke the first 12 bolt I would have saved a time of money. But I would have missed out on the opportunity to rebuild and repair it over and over and all of the tools and experience that allowed...

[tjsblazer]

Originally Posted by Tony454

Honestly I'm planning to do a four inch lift and 33's. I'm thinking the k5 will have better highway manners with the 3.73's. and also planning to run an o/d trans so getting the rpms down a little more for that would be good. Thanks for the input, it reaffirmed what I was already kinda leaning towards.
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Make sure you run the numbers through a gear ratio calculator and ensure your cruise rpm match your engine. Don't know what OD tranny you are planning on installing but the popular ones are 700r4 in an auto and nv4500 in a manual.
On 33 inch tires at a 60 mph cruise with 3:73 gears the 700r4 would turn 1595rpm and the nv4500 would turn 1709rpm. Bumping up to 4:10 gears would raise the rpm to 1753 and 1879 respectively. Will your engine run happy in your truck cruising in these ranges.
Run different numbers yourself at
http://www.grimmjeeper.com/gears.html

[Tony454]

That is a great point! Planning to run a pretty stock 454 with bolt on fuel injection so it should like the lower rpms. I have a 700 already bolted up to a np205 so that's what I plan to use if I can build it strong enough for the 454 and 33's. not planning to beat on it to much so the tranny should take what I want to throw at it.
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[Mike C]

With the 700 I would definitely run the 4.10. You will most likely need driveshafts made so I would do all the mods at the same time.