My Millennium heads are about to head off to Bob at Modern Cylinder. He is going to find the max potential out of the heads for me. Jeff told me years ago he could get over 600cfm out of them if they were going on a blower motor. Once Bob gets the ports finished, I may order a solid set.

My castings have the "billet exhaust flange" pattern. Not sure what is matches (top fuel Brad heads maybe??)