I think you misunderstood why I quoted you. It was so ralph could look back and see what HIS quote was about. HE referred to the TW as having trouble with clearance problems where the AFRs would not, which in the case of small block Fords, just doesn't happen. I totally agree that the AFR heads can have the problems you describe. Partly, because I cannot run them on my car at all without fly cutting the pistons. The TWs on the other hand... straight bolt and go. So if the TWs will fit my slightly higher compression flat tops with not valve reliefs they'll certainly fit the later model Stangs.