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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: hammerhead300 on April 19, 2010, 09:33:41 am
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Yep, you read that right... I'm looking to do the exact opposite of what most people with a 73-87 Chevy want to do. I have a '78 Scottsdale with a 14-bolt full floater with 4.56's, which would be great if I had a 4WD that I intended to build as an off-road truck. However, it's a 2WD, and I have no intention of converting it to a 4WD unless I swap the body to a 4WD chassis. My truck's going to be strictly an on-road truck, and I'll be hauling nothing larger than a pair of dirt bikes with it, so one way or another, the big axle's gotta go. If I do swap for a half-ton, I'm sure I'll end up getting one with 5- or 6-bolt hubs, and if that's the case, I'll have to swap out the front hubs too. If I go this route, will I be able to swap a half-ton axle in directly in most cases, and will it be feasible for me to swap in matching bolt-pattern hubs for the front end?
My other option would be to buy a half-ton 4WD, which I can do for $300, as I know where I can get a '76 GMC Sierra Classic. The body on my 3/4 ton truck's in much better shape, and the half-ton 4WD comes with a flatbed, so I could just swap the cab from the 3/4 ton to the half-ton if I decide to buy it.
Which will be the easier and/or less expensive option for me?
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Get the 4x.
Especially since you said dirtbikes.....
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Just change the gears in your 14 bolt.
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There are plenty of 3/4T Suburbans out there with 3.21 gearing...
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There are plenty of 3/4T Suburbans out there with 3.21 gearing...
I'm gonna have to look for one of those. I know the deepest gearing I could find for a 14-bolt corporate FF was 3.42, and the price on those gears (before I'd even get into time and labor for having someone do the swap) wouldn't get paid for by the increased gas mileage very quickly. Would it be a direct swap from the 14-bolt FF to the burban axle?
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yes a direct swap. if you were going to swap gears i don't think they make lower gears for the 14 bolt since you have the 4.56 and higher housing iv only seen the 4.10 and lower differential that will accept a thicker 4.56 to make them fit. so i would think you would have to swap out the axle if also found that 4.10 are more common than 4.56 in the 14 bolts but i would just look around for a lower ration 3/4ton instead of swapping cabs around. but if you have too the cab swap wont be that hard
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So which axle is the one that would most commonly come with 3.21 gearing? I see that 84-91 Suburbans had the 14-bolt SF axles, but from what I understand, most of the 14-bolt SFs came stock with 3.73s. I'm guessing I should be looking for a 12-bolt, but I want to make sure so that it'll be easier for me to find what I'm looking for.
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the 14 bolt i think the lowest it came with was a 3.42. the 8.5 10 bolt you can find the range your looking for but i cant help ya on what common with them never opened one up but i would think 3.73 would be about right for them but thats a guess