Frames

[Justin84k10]

Hello, I recently purchased two frames in a package deal, a k20 frame with a 12 inch lift which just has axles and leafs on it and a 350, auto trans and t-case. The frame is in good shape but I bought it with a c10 frame that still has pretty much everything but the body on it. The c10 frame is in better shape and I want to convert it into a 4x4 frame and put 3/4 ton suspension with the 12 inch lift under it. I am curious what is involved in making a 2wd frame into a 4x4 frame. Any help is appreciated, thanks

[zieg85]

You have a lot of work ahead of you.  Best to set the frames side by side.  It will be pretty apparent on what all needs to be swapped over.

[hatzie]

I believe the 1/2 ton and 3/4 ton frames are enough different that you can't make the 10 into a 20 series by swapping on the 3/4ton suspension.
Measure the C-Channel of the frame.  I believe the 3/4 & 1 ton frames are wider across the C.  I also read there were differences in frame thickness between years.

[Greybeard]

There is a difference between frame thickness and widths. 3/4 tons are heavier and wider. As for turning a c frame into a k frame? Good luck. The C-frame, to my knowledge, does not have provisions to mount the rear shackle of the front springs. This is not a game stopper but it is a fly that needs dealing with. Another point is there may be variation on the where the tranny mount is as well as the T-case cross member holes might be lacking. Still not a game stopper but needs looking at. The frame width simply needs the axle housing mounts cut off and re-welded in the right spots, as well as possibly the shock mount on one side (or both). Otherwise the 3/4 ton rear springs will bolt right on as long as the springs are the same length. If not another fly in the ointment.

So now the 64 thousand dollar question....why?

It would be so much easier to take the good stuff off the C-frame and put it on the K-frame. 

[Justin84k10]

Thank you for the response!
I was thinking about doing it because I bought the frames in a package deal and the k20 frame is solid but it is pitted and the c10 frame is mint, doesn't look like it was ever driven in the snow.

[Greybeard]

Fair enough...will it be a show truck?

All the pits do is lower sprung weight. 

Never seen a 4x frame that was not pitted, gives it character. Of course if you mean perforations through the frame, that's a different ball park altogether.

Sandblast the frame to remove the black oxide from the pits to see how bad they really are. If they are not halfway through use it. Brighten the steel and then paint with a good quality undercarriage paint. If you don't have a blasting outfit the rent on a large pressure tank blaster (300lbs capacity) with a trailer compressor to push the sand (85CFPM) is not at all unreasonable (at least where I live), less than a $150 a day together. Should take about half a day to blast a frame with very dry sand. (PS- the finer the sand the whiter the steel but at the risk of taking longer to do) We used silica sand most often at work to sandblast crane booms, equipment sheet metal, and whatever we needed cleaned. We used Black (Magic, Beauty, Diamond depending the supplier) (a basalt type sand- AKA coal slag) pretty often, it cuts fast and furious and leaves the steel with a raspy feel good for industrial coatings that don't need to be glossy (just what I found over the years). We used to use playground sand but it generally has too much silt and clay in it to leave the steel clean...use that at your own risk, silica is the same, good blasting media, bad mojo for the respiratory tract, so it is highly recommended that you (HAVE to) use (and should anyway if blasting outside a cabinet) a GOOD organic respirator with double filters or if you can afford to rent it, a fresh air supplied blasting hood AND a respirator. I am far from overly cautious, but lungs, livers, eyes, fingers, etc. are really hard for the human body to reproduce once lost. I'm nearly sixty now and I have been immune to all the common safety rules most of my life, I am now regretting a lot of my superhuman attitudes. However, I still have healthy lungs.

I've never used soda blasting or any of the organic blasting media such as walnut shells or egg shells so I can't comment on them.

[Justin84k10]

Yes it will be a show truck! Thank you for all of that information I really appreciate it! I will be getting to this truck as soon as my beater k10 is done which should be in a week or two. I am going to look online for places to rent a sand blaster right now.

[Greybeard]

Yes it will be a show truck! Thank you for all of that information I really appreciate it! I will be getting to this truck as soon as my beater k10 is done which should be in a week or two. I am going to look online for places to rent a sand blaster right now.

I just want to modify what I said earlier a little bit. I said black oxide, I did not mean that. When sandblasting the pits out they are filled with iron oxide (rust) which turns black when it gets heated up with the friction of the blasting.

I said the silica sand is the same as the playground sand, what I meant for that to mean is the silica sand needs to used carefully and with some sort of absolute cleaning type of breathing apparatus because it is obviously nearly pure silica. Might not even be legal to use in some areas. It's not worth the chance to breath even a few ounces of it in. However, to be fair, just like some lifetime three pack a day smokers never get cancer or any other lung disease, not everyone that breaths in silica (or asbestos for that matter) is going to get to silicosis or mesothelioma. It's one of those things where you pays your money and you takes your chances. Or not. It's best to 'not'.

The organic blasting media is primarily used for paint and coatings removal, or flash rust removal, they are not considered as an aggressive cutter, just a cutter that does not harm thinner metals by warping them. Soda blasting ....I have no idea what it's used for. But it seems to be popular with the automotive folks. 

[87max]

Get a tape measure out. You will be doing yourself a favor. I've bolted in several 3/4 ton axles in 1/2 tons. No issue.c to k frame Change the rear spring hangers to the 4wd as they are extended to increase ride height. Unbolt the coil tower cross member , bolt on front spring shackles to body mount and drill the frame for shackle mount & bolts (7/16 to replace rivets). None of it is a big deal. As far as blasting call around and get a price most large fab shops blast, its not worth the time to do it yourself. I have blasted & subbed it out rarely do I bother doing it myself anymore. & yes the frame conversation isn't a guess its in the garage.