I bought most of my stuff from Midwest (JE Pistons, billet rods, 3" steel stroker crank, moly push rods, titanium valves, double springs, roller rockers, roller lifters, copper head gaskets). Midwest also did my machine work on the block (bored and sleeved to 3.307) and assembled the bottom end and balanced the entire rotating assembly. The roller cam, intake, carb and billet wheel (with-out fins) were bought through E-bay. I ran a stock 20 hp for a year while I built this engine and never had an issue with it. The factory lifters will limit you to 4500-5000 rpm and the factory rods seem to hold up to this point.
Jack Jones
Hard Case Racing