Your right Brian I missed putting the "A" in there. Should be a TRA-10D. Yes, it was re-motored some time prior to my owning it. Was pulling the tandem disc in fall plowed ground and was working pretty hard and smoking some. Uses oil too. Have no idea how long the 10 has been in there. Guy I got it from had a self powered tiller on it. Said he bought it that way so who knows. I have a 14 hp Tech but won't cut a hole in the hood for that engine.
It could be done, but there would have to be a lot of modification the the tractor.Won't just be a simple bolt on. Probably have to lengthen out the frame and hood. Would the attachments then fit ? How do you intend to use it? A modern Briggs,Kohler,Honda,etc. would be much easier and not have to carve up the tractor so much .It pretty much all depends on how much of a project you want to tackle and how well your shop is equipped. Just my thoughts. Check through the archives, lots of guys hare have done some very nice re-powers on these tube tractors. If the big Wisconsin swap was done properly [with a lot of modification to the tractor and possibly the attachments too] it would be quite a conversation piece for sure. Wouldn't lack for power.
Went and looked at the mower yesterday. You guys are right - engine is far to big for a tube frame. Will wait for the right one to come along. If scrap prices were higher I would buy it anyway and scrap the mower and keep the engine.