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post #1 of (permalink) Old 09-14-2002, 05:01 PM
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10 bolt to 12 bolt?

how can you swap a 12 bolt in a truck that has a 10 bolt rear end?, im really curious, and where could i get a 12 bolt for a shortbed chevy 1\2 ton 4x4 truck? and how much would it cost to swap approx?, and what would have to be replaced? thanks guys.
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post #2 of (permalink) Old 09-14-2002, 05:34 PM
 
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Re: 10 bolt to 12 bolt?

I would think you would just have to have the same gear ratio, and then just pull your 10 and put in the 12. course might be more complicated
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post #3 of (permalink) Old 09-14-2002, 08:54 PM
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Re: 10 bolt to 12 bolt?

I'm pretty sure they stopped using the 12 bolt in 1980.

All you'd have to do is find one with the same ratio. If you happen to be blessed (haha) with 2.73s then you'll have to find one with 2.76 gears. Other than that, just bolt it in.

I'd wait for a 6 lug 14SF though. There's a guy that has a 8 lug 14SF for sale for $100 but I don't know if you can convert them to 6 lug easily and cheaply.

The 12 bolt is around 30% stronger than the 10 bolt for big tires. They handle horsepower just fine, it's just big tires and low gears that do them in. If you run 3.73s or taller it'll handle 33s just fine.
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post #4 of (permalink) Old 09-14-2002, 10:38 PM
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Re: 10 bolt to 12 bolt?

wrath, it's one of those GM things.............you know, where officially the change over was one date, but they kept using stuff or doing stuff the old way for years..............I've seen a 83 GMC K5 with a D44 and 12 bolt, and I'll be damned if they weren't stock. Had enough grime on them, and the guy hadn't modified a thing on the truck, can't see why he'd put them under it. He claimed it was all stock, even ran the VIN on one of those lemon websites to see what year it was, checked out as an 83.[img]images/icons/tongue.gif[/img] GM's weird like that.

If you can operate a drill and tap and die set with confidence and accuracy you can convert the 8 lug 14SF to 6 lug rather easily. Just have to make sure your measurments are bang on. Guys on CK5 did it for $200 with a shop doing it, and others did it themselves for pretty cheap, just having to get new studs for them.[img]images/icons/tongue.gif[/img] I'd pay for it, I'm not that mechanically inclined, I'd screw something up.[img]images/icons/tongue.gif[/img]
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post #5 of (permalink) Old 09-15-2002, 08:57 AM
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Re: 10 bolt to 12 bolt?

For that $200 they could have had the hubs on a 14FF machined down to 4.20" and drilled the hubs. They'd have a real axle then. I'm going to do this one of these days when I'm back at my parents'.
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post #6 of (permalink) Old 09-15-2002, 09:57 AM
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Re: 10 bolt to 12 bolt?

First off a 12 bolt will bolt right on to the leaf springs. I put one in my 86 pickup when I blew the gov-loc. Opened it up to find a detroit c-clip locker inside. From what I remember the pinion yoke sits about an inch and a half back from where the ten bolt did. I had to buy a combination U-joint from the parts store, because the caps that fit in the yoke were different. I found the 12 bolt to be strong and agile off road. But its true, big tires will eat half ton rear ends up if you walk on it enough. But I have heard of guys running up to 38's with no problem. In my jimmy I have a 14 bolt SF out of a 91 or 92 extended cab half ton with the heavy duty suspension package. It has the 6 lug axles and a real limited slip (not gov-loc AKA. Booom, grind, uh oh there goes one of my tires and axles). I bought the rear end for 400 bucks and thought right on I'll just slide it in. WRONG, had to pay a welding truck to move my spring perches and shock mounts to the tune of 200 bucks. But The money I think was so worth it. The heavier rear end plants nice one the hill climbs. Even though it is limited slip and I have an open diffed 10 bolt front, I can stop on a steep hill, plop it into granny low, and carry on. So just depends on the budget. But like my saying goes, if it breaks, go bigger! I hope this helped some
post #7 of (permalink) Old 09-15-2002, 01:51 PM
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Re: 10 bolt to 12 bolt?

I can't see converting a 14FF to 6 lug. Spending money to grind away metal and put fewer, smaller studs on it. Find a 8 lug 10 bolt or D44 and go from there. Convert your 6 lug one to 8 lugs. Hell, guy I work with has an 8 lug D44 with a twisted inner shaft you could get for less than $100.

The nice thing about the 14SF is it's smaller and lighter than the 14FF. Has something like 1.5" more ground clearance out of the box. The guys who were running them were more into rock crawling, so the 14FF had clear disadvantages since they weren't running 38" or bigger tires.
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post #8 of (permalink) Old 09-15-2002, 02:29 PM
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Re: 10 bolt to 12 bolt?

I can get an 8 lug 10 bolt for $125.

However, 6 lug is what I want. Why, you ask? Wheels. 6 lug wheels are cheap. 6 lug wheels are plentiful. I have 3 sets of 6 lug wheels. When you're on the trail with a bunch of guys, at least one other person will have a 6 lug spare tire you can use. Chances are the guys running 8 lug are running 38"+ tires.

14SF = weaker than a 14FF. Locker for 14SF = very expensive. Gears for 14SF = very expensive. 6 lug 14SF axle itself = very expensive.

14FF with disk brakes and 6 lug = cheap bulletproof axle. You can use the same rotors as your front ones and any 1/2 ton or 3/4 ton caliper.

The whole reason why I'm going to convert a 14FF to six lug disk is that it is cheap and bulletproof. By going with disks and shaving the hubs i'm going to lose a lot of weight and increase stopping power over a drum brake equipped axle. It'll only weigh a little more than my 10 bolt plus the rotors will only be $22 and a set of pads $16.
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post #9 of (permalink) Old 09-15-2002, 09:58 PM
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Re: 10 bolt to 12 bolt?

This is just another situation where we will have to agree to disagree. Neither of use will convince the other of our views on the subject.
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post #10 of (permalink) Old 09-15-2002, 10:11 PM
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Re: 10 bolt to 12 bolt?

Yeah, I know what you mean. I just don't buy into the whole 14SF thing though. If I had one, I'd use it. However, I won't go searching for one (because the cheapest 6 lug 14SF I've seen was $350). I've heard of them breaking ring gears and c-clips. In my opinion, if you're going to invest in a 14SF for rock-bashing you might as well go with a beefed 12 bolt or Ford 9".
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