[GScivic7]

Headwork isn't necessary for boosting a motor. The only time doing some headwork would really be completely necessary is if you've exhausted all other options and still want more power or you floated a valve or something from revving too high. Cams, cam gears, and new valve train can net you 40+ whp depending on the specs of each.

Building up the block is completely necessary if you want lots of power. Forged pistons, conrods, and re-sleeving the cylinders is a must for higher hp applications.