Scott Danforth over on StoveBolt & HAMB has a S-10/GM Metric based IFS crossmember for 1947-1955 GM trucks that he makes.
Plus you're able to use a rack w/his set up.
Bet part there is no frame swap or sub-framing involved.
It's a weld in unit like the M2 and other kits.
I personally haven't used his kit but several folks on both sites have bought them....joe