360 hydraulic lifter failure

i would strongly recommend you just go ahead and do them all now.

you'd be shocked by the amount of manufacturing junk that is left in these. an ounce of prevention at this stage is worth a pound of gold.
I only said I was going to do them all if it fixed the one I know is screwed up because if it doesn't fix that one, I'm going to toss and replace them all. And this time I'll take them all apart for a cleaning before installing them.

I suspect there is more than one with the same problem. I could've pointed them out when I was running the valves because they would bleed down and I'd have to prime it to pump them back up.

Inexperience bit me here, but thankfully I was thorough on other things so the cam/lifters survived break in.