I've got a 1940 3/4 ton long bed truck that I would like to convert to a short bed. Are the 40 and the 41-47 frames compatible? The reason, I'm thinking about going to a 41-47 frame is that they seem to be more available than the 40 frames. I'm going to keep the straight axle and keep the Classic Performance 6 lug disc brake conversion with a saginaw power steering, pitman arm unit. Any info in this type of swap would be appreciated. Thanks Runningiron