Mach 1
There is definitely some validity to what your friend said about purchasing an assembled short block being probably easier and cheaper. I'm just big on knowing exactly who is doing my work and like to be very involved in the process. Therefore, I had a local machine shop that I know (Fowler Engines) do the machining and a friend/local engine builder do the assembling.
Good point on the crank too. DSS and others I spoke with suggested that the cast crank would handle 650 HP - probably more than what even a girdled 302 block can handle. However, I'm 'Mr. Overkill' sometimes and decided that with the boost, I better get a forged steel crank. More than anything I wanted peace of mind.
If you don't mind, it would be great if you could keep us posted on your friend's 331 build-up.
E