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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Rear Drivelines, Drive Axles and Gearing => Topic started by: timthescarrd on March 04, 2014, 02:07:32 pm
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Hi all,
I have an '83 K10 that is my do-it-all truck. Sometimes it acts as a daily driver, it has to go through snow and ice (mostly snow), It goes offroad (rocks and sand - rarely ever see mud out here) When it rains I like to jump through puddles. It also hauls stuff (lumber, dirt, rocks, furniture, motorcycle). I have had a cubic yard of dirt in the bed. Hauled probably 1100-1200 lbs of gravel.
Right now the truck is stock height with 31" tires, 350 engine, 700r4, 2.63 gears 10-bolt front and rear with Gov Lock. It has problems climbing some of the hills around here without a load but it'll do it.
My plan is a 4 inch all spring lift with 33" or 35" tires, but before that happens I need lower gears. I'm thinking of going with 3:73 or 4:10.
So what I'm wondering, Should I try to get a set of 3/4-ton axles (D44 front 14FF rear) which will require new wheels or just go with new ring and pinion gears for my existing axles?
If I stick with the 1/2-ton axles, would I benefit from going with 3/4-ton springs?
I definitely want to stick with some type of locking diffs. I don't see that I'd ever need to tow anything more than 5000 lbs tops.
Thought? Questions?
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Those are some pretty high gears that you have now. Hence not pulling hills well, I put 1 ton running gear under my play toy. I'm not sure 3/4 ton springs would help a lot. Your truck wouldnt sag as much when its weighed down but it could also be misleading when your guessing how much weight is in your truck (cause your use to seeing it sag at x amount of weight) that's just my thought though someone else may have better info or opinion than me.
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Switching the front 10bolt to a D44 isn't an upgrade. 3/4T trucks and 1/2T Trucks used the same front axle. The ratio should be 2.76.
The 3/4T rear springs are longer than the Standard 1/2T but the same as the HD 1/2T. you have to move the rear mount to use them though.
If you want to lift it the springs would have more capacity but it my ride stiffer.
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With what you are planning, and keeping it a all around vehicle. I would just do the gear changes and go with 3.73:1 Ratio. You can run 4.10:1 and gain more torque and power for hills, you will not Cruise as well.
You could always see if anybody around you has a similar set up to see how theirs drives.
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If I were looking to upgrade I would search out a set of 1-ton axles.
The Dana60/14-bolt from an old army truck will be stouter than what your engine can break and with the OD tranny you still won't be maxed out on Rs.
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If you jump to 35" tire you definitely want to put higher or taller gears. I sourced a 3/4 ton 14 bolt ff off of craigslist for 200 dollars. It has disc brakes and came with 4.56 gears for my 85. Now I changed my transmission to a five speed to get the highway cruise speeds I wanted. Find out what the transmission gear ratios are and run it through an internet calculator on tire size, axle ratio and speed or rpm. Do your current ratio first and record the numbers. Then find the combo that gets you the closes to stock. The front axle can be had from any near year 3/4 ton. If you choose to go this route pay attention to the width of the rear axle you are getting. Your stance will be slightly wider than it is now which IMO makes it look better. Then you have to change the rims to match the eight lug pattern. It can be done. Shouldn't require any driveline changes either as the 14 bolt is a bolt in change.
14 bolt options are massive depending on your welding skill. For bolt in changes you need to find them off another square body truck but don't expect disc brakes. Mine is off a 2001 silverado. I had to cut off and weld new spring perches on.
Gearing will change your truck a lot while hauling and towing. It's just important to look at the entire picture of what you are changing.
Check this website for your transmission ratios:
http://www.vibratesoftware.com/html_help/2011/GM/gm_transmissions.htm#4spatrn (http://www.vibratesoftware.com/html_help/2011/GM/gm_transmissions.htm#4spatrn)
Then try this website:http://www.fourwheeler.com/how-to/wheels-tires/129-0604-choosing-the-right-ratio/ (http://www.fourwheeler.com/how-to/wheels-tires/129-0604-choosing-the-right-ratio/) to figure out what gear ratio you need. New tire diameter divided by old tire diameter times your current axle ratio = new ratio. If you truly have 2.73 and not 3.73's then 3.08 would be your best gearing with 35" tires.
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Hate to be the spoiler but give us budget? If there's no budget then x2 what Engineer said!!!!