318 300-350 hp goal : now 323 cu.in
I would do magnum style heads. Remember that those with the crummy barrel ram and an extremely wimpy stock cam makes 230hp and 300lb-ft NET with all the accessories and the stock manifolds.
My friend and I built a 94 318 magnum for his demon, where everything on the short block other than the cam and valve springs is stock and we used a small hydraulic roller from Lunati. I wouldn't be surprised if this made right around 300hp and its very torquey and also daily driveable. The car has a stock 904 with a stock converter and 3.23's.