[AcampoDave]

The article I linked earlier says 307 heads had 70cc's and Vortec heads are 64cc. Obviously a guy cant just believe every article he reads on the web, but it was written by an editor for Carcraft who has authored books on small block Chevy performace. Unfortunately for guys like me who lack real world engine builing experience, we have to turn to the Web and read thru multiple pages to research the building of a modified engine. I did that here on this site about a decade ago when I wanted my 283 rebuilt. I was greatful for the many active posters we had at that time who willingly shared professional grade knowledge about an engine that ceased production when I was still watching Sesame Street.