When trying to do these swaps, I think it best to find info from Manufacturer of the loader that shows the Base mounts used on the particular model of tractor you have. Might be some didn't get made for just any tractor, and not available, but don't know. Most loaders are the same from uprights out, and maybe even the uprights if they unbolt from the main frame. Problem is Where is the main frame connected to the tractors frame on each model. I would think one would have to find pix and parts pages of the frame and copy it as close as you can from standard metals and mount rest of loader to it then. Pretty sure you would not find JUST the frame somewhere for your tractor alone, so making it is the way to go. How about looking at those plans offered on line and see what they do for your tractor and maybe can copy their idea?? Might have to buy the plan to get info.
Hi Joe good to see another MI guy here and welcome to GTtalk. Could you post some photos of the loader you plan to mount to the tractor? Last I knew these sears loader are just to small to fit on a large frame.