I have bookmarked this and all other posts on this topic. Thanks guys, I really appreciate it!
Ford valve train sux. Piss poor hydrolic lifters, weak rocker arms
I'd bet you have a lifter or a few gunked up or rusted if it sat a while.
You can check them if you know how to watch the rotor button in your distributor, hand turn engine to get to firing position on 1 cylinder, see if the push rod is snug on intake and exhaust. If it's sloppy, that lifter is probably stuck, hand turn to #2 cylinder firing position, check pushrods, keep going until you get all checked.
You have to pull the valve covers to get to the pushrods and you have to have the cylinder your checking in firing position (both valves closed).
A quart of MMO, seafoam, Lucas, diesel fuel or mineral spirits in your oil, run for 10-15 min, change oil and filter.
MMO and seafoam probably my favorite store brand for valves but all the other have worked before.
You could also have worn and weak valve springs causing the detonation