Pretty much what these guys said. The heads are WAY too small for that cubic inch. Teh block MUST have some serious work to stay stable long term. It needs the girdle and caps at minimum, and the block better be perfect in terms of casting. The cams you shoudl START with are in the .600 lift range. Those will be hi torque, low hp cams. I would be planning to run 1.6 rockers (dont forget to enlarge the pushrod holes for the extra clearance). The belt drive is not a must have, but it will help the block live too with reduced harmonics. Teh heads to begin with are Indy -1s, and I'd have the ported. It doesnt sound like you have done the right amount of homework for this engine. Be careful, or you'll be doing it more than once.