So how do you adjust them when you have hydraulic lifters? JGM showed us how. With both valves closed at top-dead-center of the compression/ignition stroke, tighten the adjustment until there's no rocker arm play. Then slowly tighten the adjustment and watch the lifter piston. You want one-half travel, which doesn't take much adjustment. Never go further than one-half travel or you risk valve to piston contact. What's more, engines don't run very well when valves don't seat. If you've decided to go with a mechanical camshaft, valve lash is 0.022-inch cold and 0.018-inch hot.
Paint It Right
In our travels, we see Mustang engine compartments that haven't been treated to the right colors and finishes. National Parts Depot set us up with the correct engine paint finishes. Most Mustang restorers use Duplicolor or Krylon engine paint for spot-on accuracy in terms of color and proper finish. We're using Seymour Hi-Tech Engine Coating, a heat-resistant satin black for block and head, which is also acceptable.