They will certainly bolt on, but you will have port mismatch (D port vs square port) and you won't know if they clear until installed. You'd also need fabbed mids to mate up with them since your stock exhaust won't work and neither will the GC 's. Easier to either get 03-08 5.7 shorties that bolt right to your stock exhaust or something like Pacesetters that have an available matching Y pipe.
The port match is not a problem, as the square port size fits in the d port just fine- if going the other direction it would be. The fitting in the truck was the main question here, has anyone tried this?
I have a set of these, I guess I'll have to try them on mine when I get the time, . These should flow a lot better than the stock ones, I have tried the JBA shortys, they were great- but performance wise not much of an improvement (butt dyno). I am thinking that the 6.4 manifolds will be as good as the shortys, maybe? Pipes are easy to build.
Factory SRT manifolds are literally just OEM shorty headers. They will be better than your stock 5.7 logs but the unknown about clearance (both manifold and mid-pipes) is the kicker. The old 4th gen trick before they came out with long tubes for them was to use the Gen 1 SRT GC manifolds:
More like a mid-length and it was that extension that allowed them to work in the 4th gen Rams when the LX/LD versions would not. Take pictures lol.