Best 273 and 318 builds (NO 360's please)

1 Pt. of compresion is worth about 3% on a mild build. However, other things fall off with the power. Like how effiecenty drops off. You'll use more gas with less return.

Also, with the larger heads, build dependent here, the larger port will slow down the air and fuel dropping the fuel out of suspension if it can get it into a fine mist at all to begin with.

A finer mist will burn quicker and more completely than big droplets. Again, this is build dependent. Bigger ports for higher RPM. If your going to ignore the RPM below , lets say 3,000, then a 360 head could make for a fine drag head in a lightened Duster/Dart etc......

In doing a performance build via a rebuiuld of the engine, the use of a good slug over OE slugs will show alot more gain than just adding up 3% by the possible point gain. Lets just say going from the actual less than 8-1 to 10-1+ ratio. You'll have a great quenched area over the cavranous concert hall chamber that will help alot with the increased cam size.

Working the package in full nets huge bennifits over band aid approachs or AKA the poor man's way of increaseing performance.

Do what ya can! So long as it is fun!