UPDATE: I pulled the cooling tins off and the engine was clean, but I did scrape out the cooling fins to make sure. Still lost power and finally died. I wasn't getting fuel. Bypassed the fuel pump and ran it as gravity feed and it cranked and ran. I replaced the fuel pump with a new plastic one, which promptly broke. The pump arm cracked, I am 99.9% certain I had the arm on top of the cam as instructed, the new plastic pumps are cheap. I rebuilt the old metal pump using a kit I ordered from here http://www.then-now.com/ (great product, great service, highly recommend them) and hoped I had the problem fixed. Nope, same thing ran great for a while then lost power.
So, pulled the carb and opened the valve cover and the valves were WAY out of adjustment. Intake barely had .002, don't know what exhaust had because I started adjusting before I thought to check, but it wasn't probably .007 at the most. So, hopefully the valve cover gaskets and carb rebuild kit will be delivered tomorrow, I figured while I the carb off I may as well clean and rebuild it as well. I will let everyone know how it is running once it is back together, but I am pretty certain the valves were the problem.