37s on a half ton with a 12 bolt with 4.10 gears

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Isaac nickerson

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Hey all, wondering if doing 37s on a half ton with 12 bolt back 10 bolt front and 4 10 gears would be a slow turd? Gotta stock 70s 350 and a sm465. I am dailying it so I don't want to regear to anything to crazy... but I will be wheeling it quite a bit too. Any advice would be much appreciated n
 

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I run 37s with 4.10 axles, but 14 bolt ff in rear. Front 8 lug 10 bolt. For daily type driving gears are actually ok for me. With wore out 305, dump truck acceleration. For serious off-road, better gears would be nicer.

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BKING33

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Previous Square I drove had 36" Swamper's and 4.10 gears. I had a stock 350 and TH350 trans.
It was fine normal driving, but was a little sluggish on accel towing heavy.
 

Isaac nickerson

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How about the 12 bolt? Do you think it will hold up to that big of tire? And If i were to seap to a 14 bolt, do you have to get 1 ton suspension too?
 

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In stead of the 12 bolt, I would be worried about the brakes. It's not going to stop well with 1/2 ton brakes.
 

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Hmm, good point. would it be worth converting to discs in the back?

In my case, my K15 had a 12 bolt, but 3.08 gears and a peg leg. It already had a 4' lift and 33's. I didn't like the wheels it came with and by the time I changed gears and wheels plus add a posi, it wasn't going to be worth it. I found a set of 3/4 ton axles with 13" rear drums and a limited slip for $400. I got a set of wheels on CL for $100.
 

Isaac nickerson

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Another question: do you have to have 1 ton suspension to run 1 ton axles. I am wanting to buy the 6 in rc lift for the half ton but I am wondering if I would need to get the one ton kit instead?
 

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Ok I'm messing with ya Isaak.

I'm answering a question you haven't asked yet, however you did ask if a 10 bolt would hold up. And ... no. :Nonono:
But there is always someone who will argue.
Because,
of all the ways a truck can be used and abused.
Even 32" tires can meet metal if you twist it enough. (you know, the front tires contacting the rear of the fender opening).

If you stay within 33" on a half ton suspension, and 4" of lift you will be in the sweet spot
for general work/play. Even working in the bush, like in BC for example driving up logging roads everyday and facing dry washboard to slimy mud, a truck with this level of mods will certainly fare better than stock.
Even 33" can break those stub shafts with ease, if you're a dork..

Bigger tires need lower gears and D60/14bolt. The extra weight doesn't hurt either not counting fuel non-economy.

You can tip toe to the mall with bigger tires on 1/2 ton axles, and maybe a few days in the winter up and down the driveway. If you don't break anything, eventually one day on the highway you'll get the death wobble and crap your pants. When you dig into the frontend to see what's loose you might get a shock. You won't find just one sloppy joint if you get what I'm saying.

Some guys are happy with big boots just for the look.

If you go to 6" lift springs, things get a lot more complicated... like longer driveshafts. Not
too much fun. If you go manly with a D60, it's larger housing sits taller than a 12 bolt, or older D40 they had in the 70's. Then 4" lift springs... truck will sit as high as 1/2 ton on 6" lift.
Want more? A 1" body lift. Never more.
Still want more? A 1" Zero Rate at the bottom of the spring pack and while you're down there installing it, use the forward spring pin hole to move the axle forward one inch.
THEN you can run 36" tires and aaaalmost not rub the fenders if you're still careful. Make sure the cab is slid bacl on the mounts as much as possible... IF it even moves. Some do..?
Then maybe trim the front fanges of the fender.

Oh and flexy springs. Do some research.. may old school lift springs are way oversprung.
Oh which reminds me.. still talking abuot the front end here.. the rear shackles need to be .5" longer and heavier. Late 80's one ton 4x4s had the longer shackles. Or make them or buy from ORDs. Or DIY4x4.

I won't get into shocks here.. I have lots of opinions there too. But I already gave you way too much gravy anyway. I don't know wtf I was thinking..
 
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Isaac nickerson

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Ok I'm messing with ya Isaak.

I'm answering a question you haven't asked yet, however you did ask if a 10 bolt would hold up. And ... no. :Nonono:
But there is always someone who will argue.
Because,
of all the ways a truck can be used and abused.
Even 32" tires can meet metal if you twist it enough. (you know, the front tires contacting the rear of the fender opening).

If you stay within 33" on a half ton suspension, and 4" of lift you will be in the sweet spot
for general work/play. Even working in the bush, like in BC for example driving up logging roads everyday and facing dry washboard to slimy mud, a truck with this level of mods will certainly fare better than stock.
Even 33" can break those stub shafts with ease, if you're a dork..

Bigger tires need lower gears and D60/14bolt. The extra weight doesn't hurt either not counting fuel non-economy.

You can tip toe to the mall with bigger tires on 1/2 ton axles, and maybe a few days in the winter up and down the driveway. If you don't break anything, eventually one day on the highway you'll get the death wobble and crap your pants. When you dig into the frontend to see what's loose you might get a shock. You won't find just one sloppy joint if you get what I'm saying.

Some guys are happy with big boots just for the look.

If you go to 6" lift springs, things get a lot more complicated... like longer driveshafts. Not
too much fun. If you go manly with a D60, it's larger housing sits taller than a 12 bolt, or older D40 they had in the 70's. Then 4" lift springs... truck will sit as high as 1/2 ton on 6" lift.
Want more? A 1" body lift. Never more.
Still want more? A 1" Zero Rate at the bottom of the spring pack and while you're down there installing it, use the forward spring pin hole to move the axle forward one inch.
THEN you can run 36" tires and aaaalmost not rub the fenders if you're still careful. Make sure the cab is slid bacl on the mounts as much as possible... IF it even moves. Some do..?
Then maybe trim the front fanges of the fender.

Oh and flexy springs. Do some research.. may old school lift springs are way oversprung.
Oh which reminds me.. still talking abuot the front end here.. the rear shackles need to be .5" longer and heavier. Late 80's one ton 4x4s had the longer shackles. Or make them or buy from ORDs. Or DIY4x4.

I won't get into shocks here.. I have lots of opinions there too. But I already gave you way too much gravy anyway. I don't know wtf I was thinking..
Hahaha, I appreciate all the feedback. Answered quite a few of my questions. I have a few (probably stupid) questions though. Why are .5" longer rear shackles needed? does the 14 bolt lift the rear at all? and are there any other big complications other than longer driveshafts when doing a 6 in kit.
 

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Hahaha, I appreciate all the feedback. Answered quite a few of my questions. I have a few (probably stupid) questions though. Why are .5" longer rear shackles needed? does the 14 bolt lift the rear at all? and are there any other big complications other than longer driveshafts when doing a 6 in kit.

Glad to help.
You notice how a lift spring has arch to it. Well what happens when it compresses? It gets longer. And without extra shackle length the rear leaf eye will smack the frame. THAT is why old school lift spring have such higher spring rates... to prevent them from compressing enough to bang the frame.
And banging the frame hurts! Plus lowering the rear of the leaf increases the trail... which lends to handling and self centering the front wheels after a corner. All our beloved squares can use a bit more trail... even with the slight extra angle imposed on the front lower U joint.

I never addressed the rear end around lifting. I mean a D60, one ton front end, will lift the truck. But since you brought up the rear axle, you can use blocks but they add to wheel hop and are gay. You can invest on a lift spring or best... shackle reverse kit from ORD or DIY4x4.

Brakes...
the thing about one ton trucks that is always a win are the juice brakes. Hydro pressure comes from the power steering pump rather than the vacuum boost a 1/2 or 3/4 ton has. THESE brakes lock up 40" tires and you wanna see hippies get out of the way?

Rear discs are the way to go imo. You can use 3/4 ton front rotors and an aftermarket mounting plate. You can also run 3/4 front discs on a one ton with the proper bracket. They are just as strong as the bigger one ton rotors, but you get a better modulation and take some 35ish lbs off each front wheel.

Rear discs do not have an emergency brake unless you use Caddy brakes from the mid 70's. Once you figure the trick to bleeding them and setting them up, IF YOU USE THEM OFTEN they will give good service. If you're in to mud you will ansolutely need to keep them clean.

Back to the front end with a 4" lift spring.
Best bang for buck are Tough Country. They have the proper spring rate. If you have the $$ you can do better with a a custom ORD or Deaver Spring multi leaf pack. More leafs, but thinner. Great flex, better ride all around.
With a 4" lift it's still a good idea to use a raised steering arm. Or a lowered pitman but these put more stress on the steering box and frame.
Or the ultimate **** OFF steering is cross over.. using a 2wd steering box. You can search this out and come back for more info after your homework.

We're starting to get gnarly here..
 

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