1/2 to 3/4 helpppppp

[Bkap725]

I have an 86 k10 lookin to do a 3/4 ton swap what all do I need to change out??

 

[firebane]

Basic? Axles.

Advanced? Axles, springs, and tires

 

[Bkap725]

I wanna run 39s on the truck so I'd prob be better off doin the whole thing right?

 

[firebane]

I wanna run 39s on the truck so I'd prob be better off doin the whole thing right?

39s? That will require a lift more than anything else.

 

[Bkap725]

Well yeah I got a 3" body lift now and just bought a 6 inch lift but don't u need to beef up the axels for 39s

 

[bucket]

Yep, you want more beef to be reliable. 3/4 ton axles will literally bolt right in, just need a conversion u-joint if you want to keep your rear shaft stock. Napa Precision #447 if I remember correctly. You can use your stock calipers on the front axle too.

 

[Bkap725]

Does it have to be within the square body years for the axel to bolt right in

 

[Rule_So_Hard]

One thing I can tell you is that do not get a set of 6 lug 3/4 Axles. They are not the same as the 8 lugs.

Where are you in IL?

 

[Bkap725]

I'm in Joliet so I'd be best to get 8 lug axels and springs??

 

[Bkap725]

I've done a lot to 2wd trucks but the 4x4 world is new to me

 

[Rule_So_Hard]

I'm in Joliet so I'd be best to get 8 lug axels and springs??

Well all 3/4 axles are 8 lugs but Chevy did make some 3/4 ton 6 lug axles. It was like a light duty 3/4 ton or something....it wasn't a great idea. Anyhow...don't mistakingly buy them because they really are not any better that what you have. You are looking for 8 lug 3/4 ton axles.

I was born in Joliet and have a lot of family there. I'm about an hour away in LaSalle county.

 

[Bkap725]

Alright cool thanks man I appreciate it do u know wat year specific axels I need to somehow find haha

 

[cobra20]

try to find a 14 bolt full floater for the rear axle

 

[Greybeard]

Alright cool thanks man I appreciate it do u know wat year specific axels I need to somehow find haha

If I'm reading you right you want to get a 14bolt full floater for the rear and a Dana 44 for the front. An 86 will have front 10 bolt which is actually basically the same as a Dana just a different maker. Some parts interchange, I am not sure if 8 lug hubs will, otherwise just get a ten bolt 3/4 set of axle spindles and bolt them onto your existing tubes. The easy way is to the entire axle assembly obviously.

The 14 bolt will NOT bolt right in. That is an urban myth it is, however, an easy swap otherwise. Let me explain that I am familiar with the pre-80 vintage frames so I KNOW it's not a straight across swap in them. YMMV. However, aside from the spring perch center/center difference of about an inch they will bolt right in with new u-bolts and spring plate. Of course the shock mounts on a 3/4 ton are different also with both on the same side of the axle so that will have to be dealt with also. And the brake lines are different so an adapter will necessary if you plan on keeping the existing lines. Then thee is the issue of the brakes on the 3/4 ton, the swept area is about three times as big as a half ton which will have a tendency to lock the rear end to soon- mighty fun on wet roads. It's nothing that cannot be overcome, just go into it knowing it is not a complete straight across swap. I ran 6 lugs in front and 8 in back for over eight years on my 78 K-shorty. I broke one of the 14 bolts in that time- from operator error of course. One I had from a van and the other was from an unknown source. There are three different widths of 14 bolt ff rear ends mostly due to the hubs. If you want more articulation get a van rear end, it's about three inches wider at the wheel mounts. This will stick tires out about 1-1/2' more than otherwise. Or allow more backspacing in the wheel.

Disclaimer- I got some of my information off another website just yesterday. The parts about relocating the spring perch's, brake lines, etc. is from experience. Axle widths and whatnot from the other site.

Here is everything you ever wanted to know about the 14 bolt....http://www.pirate4x4.com/tech/billavista/14b_bible/index.html

 

[MadOgre]

K so if you use 73-87 axles the 3/4 ton axles swap right in! perches are the same and the shock mounts are the same. The only reason they would not be the same is if they came from a different era of truck.

The 1/2 ton axles came as a 10 bolt and 12 bolt using a SF design with 8.5 and 8.75 inch ring gears.

I have come across 12 bolts with 8 lugs. Don't have proof yet but I have. These will not offer any added strength over a 6 lug 1/2 ton axle

The brakes on 3/4 ton axles will not fit inside 15" rims so you will have to upgrade to 16" or larger

The 14 bolt SF came in both 6 lug and 8 lug configurations. both are a 3/4 ton axles with a 9.5 inch ring gear and large axles. They are 3/4 ton capacity except the 6 lugs limit wheel loading weight. These are large and tuff axles. Easily 3 times the strength of any 1/2 ton axle.

The 14 bolt FF is almost the same as the SF except that it uses a 10.5 inch ring gear and is a Full Float design, both of which increase strength and reliability over the 14 SF axle. It also has beefier pinion bearing design over the 14 SF

Running 39s I would opt for the 14 bolt FF although the 14 SF would be capable. The 14 FF is just that much stronger. For 35s the 14 SF is more than enough!

Seeing as you have the 6" lift kit you need not worry about upgrading the suspension as lifted leaf springs are more than up to the task. If using blocks and stock leafs in the rear you may want upgrade to shorter blocks and add a leafs or just opt for lifted rear springs too.