k20
3/4 ton status
I vote 4.10s, and I was all happy when I saw 4.10 & 14SF, thought I might be able to unload my 4.10 sf on you, then I saw you wanted 6 lug, bah.
CK5
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3.73's or 4.10's
- Thread starter steve_kibbe
- Start date
bowtiepower00
1/2 ton status
4.10's. If you are going to regear, with the 700, I'd go with 4.56. That OD is pretty deep. I've had 3.73 trucks with 33's and I wished they had 4.10's. 3.73's are decent with 31's or with 33's and no OD. Towing and hauling, you're going to want the deepest gearing you can stand on the highway, IMO.
roadnotca
3/4 ton status
I don't know if they are available for 14B but I put 3.90s in my 10Bs. Its a Hot Rod ratio made by STRANGE/US Gear. Bought from West Coast Diffs. 1985 Burb, SBC350, TH350, NP208, 3.90s, 34s.
if the choices are only 4.10 or 3.73, I say go 4.10's. 4.56 with overdrive is nice. I ran 35's with a 700R4 and 4.56's. plenty of power and decent rpm's on the highway.
Here's a couple of sites:
CHART
Edit: This one is good if you want to maintain the stock power setup. Put in your stock tire size, new tire size and current gear ratio. It will calculate an equiv. gear ratio for the new tire size. There are two or three other calculators on the site as well
TIRE SIZE/Gear Ratio Calculator
CHART
Edit: This one is good if you want to maintain the stock power setup. Put in your stock tire size, new tire size and current gear ratio. It will calculate an equiv. gear ratio for the new tire size. There are two or three other calculators on the site as well
TIRE SIZE/Gear Ratio Calculator
MaxPF
1/2 ton status
I would run 4.56's myself. If you don't want to go lower than 4.10's, then run 4.10's. OTOH, if your current axles and the 14bsf you score have the same gear ratios (as did mine) then you have a choice: regear both, or throw it in as-is and run it until you feel like spending the money and time to regear it 
.
FWIW, I'm running 3.73's with 33's, and it pulled a car trailer with a sedan on it just fine (6000lbs total trailer weight). Not spectacular, but fine. When I regear, it will be straight to 4.56's, go past go and collect $200
. That way, when I wear out my 33 inch Mud Kings and go to 35's I will be dialed in 
.
There's an article I remember seeing but can't find. The authors had an H2 and regeared it from 4.10 (stock) to 4.56's. The tires were stock size (35's), and they claimed no difference in highway mileage and a 1-2mpg increase in towndue to the fact that the engine didn't have to work as hard to accelerate the vehicle.. I dunno if it was a scientific test, and it contradicts conventional wisdon, but it at least sounds plausible
EDIT: If you need any more motivation to go with 4.56, lookie here: http://coloradok5.com/forums/showthread.php?t=184635
.FWIW, I'm running 3.73's with 33's, and it pulled a car trailer with a sedan on it just fine (6000lbs total trailer weight). Not spectacular, but fine. When I regear, it will be straight to 4.56's, go past go and collect $200
. That way, when I wear out my 33 inch Mud Kings and go to 35's I will be dialed in .There's an article I remember seeing but can't find. The authors had an H2 and regeared it from 4.10 (stock) to 4.56's. The tires were stock size (35's), and they claimed no difference in highway mileage and a 1-2mpg increase in towndue to the fact that the engine didn't have to work as hard to accelerate the vehicle.. I dunno if it was a scientific test, and it contradicts conventional wisdon, but it at least sounds plausible
EDIT: If you need any more motivation to go with 4.56, lookie here: http://coloradok5.com/forums/showthread.php?t=184635
roadnotca
3/4 ton status
They may have hit on an unintended software product that the H2 Engineers didn't explore. I have an H3 and using a heavy right foot doesn't drop the MPG by half like a non-puter, carbureted vehicle would. Its still a young Science.MaxPF said:There's an article I remember seeing but can't find. The authors had an H2 and regeared it from 4.10 (stock) to 4.56's. The tires were stock size (35's), and they claimed no difference in highway mileage and a 1-2mpg increase in towndue to the fact that the engine didn't have to work as hard to accelerate the vehicle.. I dunno if it was a scientific test, and it contradicts conventional wisdon, but it at least sounds plausible
steve_kibbe
1/2 ton status
MaxPF said:
I'm getting a housing from him, so I might just get the gears too
JEBSR
1/2 ton status
Im running a 5.3 with a 4L60E and 373's with 31" tires. I wish I had the 410's and will probably upgrade eventually. Therefor I would not go less than a 410 with the 33's. I also put a set of 456's in a 96 Z71 with 33's and a 350/4L60E combo and thought it would be to much gear for the street. I was wrong. I towed a gooseneck from Georgia to Kentucky and it did perfect. The only problem the 456's presented was that he lost a couple miles an hour on his fuel mileage when running it at high speeds. The most possitive point was that I was able to tow his 26' trailer with a 6500 lb truck in overdrive at highway speeds.
josh86k10
1/2 ton status
I ran 4.10's with 32's in my K10 (700R4 back then) for a while. Fuel mileage was actually better than with the 32's and 3.42 gears, though I don't remember the figures (sure as hell was a lot better than now with 40s, TH400, and 4.56). It actually made my mostly stock 305 seem impressive... even with a detroit out back she'd kick around sideways if you held your mouth right (it was high school after all 
). 4.10s, 700R4, and 32's was a great combination. It was my daily driver at the time and saw everything from trails to back roads to quite a bit of interstate. I'd definitely vote for 4.10's, maybe even 4.56 with 33's depending on whether your 33's run big or run small.
). 4.10s, 700R4, and 32's was a great combination. It was my daily driver at the time and saw everything from trails to back roads to quite a bit of interstate. I'd definitely vote for 4.10's, maybe even 4.56 with 33's depending on whether your 33's run big or run small.I would definitly go with the 4:10's at the minimum, and give some serious thought to those 4:56's. Espicially if you are towing 14k#s! 
I'm running 350/700/4:10/33s on my 88 and the do a very good job of providing good towing power (my boat loaded weighs about 4500#), nice hiway RPMs (1850) and good mileage (19 mpg, but only on the hiway). My problem is that I like to feel the power of my Blazer, so my in town mileage sucks to say the least (to the tune of 10-12).
I'm running 350/700/4:10/33s on my 88 and the do a very good job of providing good towing power (my boat loaded weighs about 4500#), nice hiway RPMs (1850) and good mileage (19 mpg, but only on the hiway). My problem is that I like to feel the power of my Blazer, so my in town mileage sucks to say the least (to the tune of 10-12).
