Thankxxxx............my motor`s a 400/470 stroker w/a solid .680-.660 solid roller @ 12.1 comp. I did short shift but also had fuel delivery and charging issues so who knows. I know guys are running mid/high 9`s w/em and I hope to be one of those guys soon. The porting can`t hurt anything and I`d bet it will help considering I left a lot on the table the first time around.