I'm putting in a set of ported twisted wedge heads. I have questions. Do I need a special length pushrod and how much piston to valve clearance do I have? My cam has .533/.544 lift. I know I'm cutting it close. I have a basically stock bottom end. Anybody? I know as recently as yesterday somebody said .540 is the max but I've seen .550 advertised. Please help. TFS heads are a PITA...you need special tapered head bolts too.