Colorado Swap?

[mr48chev]

With almost all frame swaps, subframe swaps and other chassis mods you are going too do some or a lot of cutting and mods. That may be raising the bed floor a few inches, trimming out front end inner sheet metal or other mods.
I've never knowiingly seen an S-10 swap using the Code 504 it that allegedly sets the body high enough that you don't trim any metal. That would be the case with swapping the 59 body onto a Coloado frame, you aren't usually going to set the 59 right down on the frame rails unless you plan to have it seriously low, you are going to space it up off the chassis a tad for clearance.

[joedoh]

if i raised my mounts 1" there wouldnt be much trimming of the lower air director at all. this is 4" off the frame. the inner would still need trimmed but thats any IFS



i picked up a colorado finally, its been in the works for a bit but i laid eyes and hands on it yesterday.



the first thing I will mention is that there will be no trimming needed except the inners for the a arms, at almost any height, because its a rack steering setup and forward of the sway bar you could just cut the frame rails off. that will allow a full depth original style radiator and no cutting of even the core support hoop.



what has kept me from working with the colorado is that the front section of the frame is HSS (high strength steel) that is hydroformed. hydroforming a frame uses high pressure fluid inside the tube so that when it is bent to the desired shape, it doesnt kink or get work hardened (weak) at the bends. hydroforming isnt the same as forging, so instead of changing the alignment of molecules by force or pressure or using heat it is literally just bent, so the application of heat can trigger the "memory" of the previous shape of the steel tube, and can get misaligned easily.

also, hydroforming mild steel is not repeatable/reliable, so it must be high tensile steel, which is much thinner and stronger than a mild steel tube. hotrodders know the difference between hot rolled welded seam tube and chromoly tube, chromoly is high strength low carbon steel, and takes more preparation and care to weld on.

this is what the front section of the colorado frame is made of, so welding mounts on will take some careful prep and bolting them on has some guidelines too. if welding, you can weld to the SIDES of a HSS frame but welding to the tops is not a good idea because you can make a weak point in the bending direction of the beam. welding also requires a good amount of surface prep and proper heat settings, too hot and fast and the new weld will just crack off the frame. if BOLTING to the HSS frame, you must use through-tubing on every bolt, meaning drilling the inside hole to bolt dimension and outside hole to through tube dimension and that will keep whatever you are bolting to it from using the outside wall as a cantilever, which can cause bending of the thin wall of the tube.

I took a few pictures of the joints on the frame, interestingly the front joint that joins the mild steel center section to the HSS front section, you can see the long horizontal overlap on the inside of the frame



and there is a second frame splice at the rear, I believe the rear section is mild steel but I will update when I get it taken apart. the rear joint is where I will be adding my length (~15") for my baby cabover project.




it will be probably thanksgiving before I start, i will make a project thread. source and full disclosure, I am an engineer, i read and research and think a lot about stuff before doing it.