I don't know much about about porting, but I know the D-port harley heads flowed like crazy and they have extra material in the floor....So I don't think I'll touch the floor on the next set I port.
I totally agree. On the 906 heads I was only correcting the too-tall factory short turn height. I'm sure harley has done their design homework over the last 30 years. As I say...technology continues to improve. Look at the new Mopar hemi. The port shapes are so much better than the 60's.