I assume you are driving this thing.... If your noise is very noticable and it is a main or rod bearing.... then your oil pressure will drop like a rock very soon after....like minutes later in most cases. (at least this has been my experience). The pressure should drop to 10psi or lower at idle and then you'll know for sure. But the noise for a bearing usually kind of sounds like slapping some pieces of solid wood together. Much more of a robust knock rather than a dainty tick or click. Not really a clicking or ticking. Ticking seems to usually be related with the valvetrain... possibly a lifter not pumping up, maybe a rocker that isn't adjusted right, perhaps a bent pushrod... or the timing chain. Those seem to be the most common problems associated with "clicking". It sounds like the guy before you messed with the heads and valve train quite a bit, so that would be where I'd start.

just in case.... check for heavy metal in your oil by poking a hole in your oil filter after removing it. cut it open with sheet metal shears and look at the element. You should see a lot of metal there. Or take a flashlight and shine it through the oil while you drain it... it will have a lot of sparkle. Get a bit on your finger and shine it under a like you should be able to see the flakes.

Yes to these tests would indicate the start of bearing failure, top or bottom end.