max lift isnt what your looking for when looking at piston to valve clearance. when the valves are at max lift, your piston is going to be at the bottom of the cylinder. look at valve events and determine just how aggressive the ramp rates are on the cam... email a comp cams tech or call anderson ford motorsports and ask what they recommend and if you dont like it look at FTI custom grind cams, they make an excellent afr165 cam combo