The best way to make power out of a 318 is
Street; Is to use the Edelbrock Performaer intake, stock T-Q or 600 cfm carb max, pocket port OE heads, headers, split duration cam with at least 6* difference, 8* is better in duration. Compersion ratio not more than pump gas can handle. 9.0-1 should be just fine.
Street/Strip; A better head like the 302 with porting and larger valves in the 302 head to a 1.88 - 1.60 (360 valves.) A Edel. RPM or equal, increase comp. ratio and cam duration to suite needs of the target E.T. (or a Magnum swap is a very good idea.) Increase exhaust size to 2-1/2.
Strip; Big everything, LOL.