If your gonna put a V8 in there at least do something less boring. 350's are cheap and over rated.
On the 6 cylinder side...really depends on how much time and money you want to spend. A Naturally aspirated Street 250 is capable of 310 hp and 280 torque. Or a mild turbo build could put you at 380 hp. Really need to know your budget and what you really want out of the engine. There's alot at your fingertips with this engine. Alot more than I think your aware. lol