your fawking up a bit
just a bit, but not in the "let's do something awesome" side of things..
in other words, the flat 90 degree weld of frame to channel iron , is going to promote cracking in the thinner frame metal.
Just make sure any flat frame welds are staggered, and you gusset spoob.
I can't stress enough to not weld straight up and down on frame pieces.
make an arrow --> out of the overlaying piece.
Oh, those frame rails won't be just welded at the edge. That would rip out immediately.......c,mon....I know better than that.
There will be A piece of 2 x 3 1/4 wall tube stuffed into the open end of the isuzu framerail. Then will be plug welded multiple times on both sides and the top. Then that piece will extend out about a foot out of the isuzu frame and be welded to the inside edge of the channel along the bottom, and some plug welds on the back side.
Additional plates will be added to gusset. And another piece of 1/2" thick, by 2" wide flatbar will be stuffed between the upper lip of the channel, and the top of the frame section where they overlap. So the butt end of the frame will COMPLETLEY fill the inside of the cahnnel, and then be plated diagonally across the inner edge.....turning the C-beam into a boxed section, around the front frame box section, which will be stuffed with the thick tube and all plug welded......A triple box beam cross section should work right????
Also, this chassis will bolt rigid to a unibody Subaru body, so will have all the strength of the unibody to resist bowing and twisting too. So in other words it won't be like a truck where the frame has to hold everything cause the body is bolted with rubber and not designed to take any load.
Think of it as a continuous unibody spacer......rather than a standalone frame. Although I did design it so I could change bodies