318 Cam Maybe Not
Cam and heads are the 2 main mods for power gain.
Stock 318 heads have enough flow for about 300 hp with reasonable cam and cr.
Obviously to get the best out of the cam and heads a 4bbl is basically a must and headers are always good but on lower level cams manifolds will work.
4bbl headers and xe262h cam on a stock long block 318 is said to make 282hp @ 5000 rpm.