ticking not fixed by valve adjustment

Hello,

Hoping for some suggestions! 65 dart wagon 225 1bbl...My #5 cylinder had a MAJOR explosion when I was starting the car one cold morning--blew out the muffler and exhaust gasket at #5. Replaced muffler, adjusted carb/choke. Ran OK, engine sounded a little weird.

2 weeks later, on a road trip, stopped for sandwiches after about an hour. In parking lot, noticed weird clackety engine sound, but still running OK. When starting car, loud clanking noise and won't idle. No useful tools, so limped to a repair shop, and discovered no compression on #5 and #5 pushrod had bent. Adjusted things enough to drive car home. (yes, I do tend to torture my old slants)

Replaced #5 pushrod, checked all and #4 was also slightly bent. Replaced #4 pushrod. Replaced plugs, adjusted valves. Tick. Adjusted valves. Tick, adjusted valves, tick. Irritating tick. Adjusted valves, tick. Horrible irritating tick. Sounds like only one tick, not all cylinders. Louder at slow speeds. Car has power again and seems to run fine, didn't re-check compression because it runs fine. Didn't replace exhaust gasket yet because I might have to pull whole thing apart.

What do you think is ticking? Anything I can check/fix easily to rule things out/in? Where is my smooth running slanted engine? Did I kill the head? Head was fairly fresh--replaced about 2yrs ago.

Thanks for any ideas...Ann