I have a 78 k10 with 35" tires. The 10 bolt rear end blew out, witch was only a matter of time. So I found a 14 bolt sf 6lug out of a 89 2500. Buy looking at the 2 the spring perches and shock mounts dont line up. I thought it was a direct swap. So my question is what do I need to do to get it to fit. Cut, move and reweld the plates and shock mounts? My friend has a 80 3/4 ton with a 8 lug 14 bolt sf. Would that be a direct bolt on, and if can I swap it to a six lug by using parts from the 89 one?

14 bolt bible (http://www.pirate4x4.com/tech/billavista/14b_bible/index.html) will answer all your questions

The 9.5" sf 14b (Semi Floating) is not covered in the 14 bolt bible.

I swapped a 9.5" sf 14b from a '92 c2500 6 lug into my '95 k1500 when the POS 10 bolt blew up. The 2wd axle is a little narrower WMS-WMS. Mine bolted right in, spring pad width was the same, I'm not sure about your 76. 1/2 and 3/4 ton spring pad width *should* be the same, 1 ton spring pads were narrower.

Cutting off the old spring pads and welding new ones is pretty simple. Even if you don't have a welder. You can set the new spring pad width and pinion angle, then mark the perches. Find a friend with a welder, call a mobile welding service, or load up the axle and take it in to the welding shop.

the spring pads on your 89 axle are wider than your 76 so all you have to do is remove the spring pads and reweld them in their new location

On the 14sf axle there the spring perch's and then theres some other flat part, but nothing goes on there. Do I need them or not because there in the way. Also were can I get new spring pads and shock mounts from?

id go to DIY4x.com i love kurts stuff and he has everything you need too

EDIT* you can cut them off

BTF is another option.

Those extra flat perches on your axle are landing pads for the 89's bumpstops. Go ahead and cut them off.

Just buy a new set of spring mounts from one of the various vendors on this site and weld them in the same locations as your old 10 bolt.

If you are good with a torch (or if you have a friend that is) you can in most cases cut off the factory spring mount and reweld it in it's new location. It's an easy job.

What about the shock mounts. Who sell them. Another thing what about the ujoint. its ont the same as a 14 bolt ff is it. Also does anyone know if 3/4 ton axels off a 80 would bolt right in.

I used a conversion U joint, 1310-1330 neapco PN 1-0134 IIRC.

The pinion is longer on the sf 14b than 10b, depending on the amount of lift you have, you might need to shorten it, or it might work just fine.

I had a a 6" lift and mine worked fine.

1 tons and older chevys have a narrower spring perch. 1 ton - 38" inside of spring perch to inside of spring perch. 1/2 ton and 3/4ton are 40" inside of spring perch to inside of spring perch.

will the 14 bolt SF spring perches fit my 04 silverado 1500?

Sorry for the hijack... :flipoff2:

should.

will the 14 bolt SF spring perches fit my 04 silverado 1500?

Sorry for the hijack... :flipoff2:

Sure. Just keep grindin' till they fit:flipoff2: