65 Barracuda daily driver

So it turns out it might not be pinging, but has more of a lifter tick. It gets worse the more you step on it. There was also a tiny bit of white fluid on the back of the dipstick. I think that might be condensation. No oil in the coolant. The engine has been mostly sitting since February of last year and only fired up and driven sporadically since April or so. There was a lot of rain when the exhaust wasn't fully connected, so condensation is possible. At startup there is water vapor coming out of the exhaust. It could also come from the coolant leak at the exhaust manifold that is now fixed.

Anyways, I changed the oil and filter (and added some Marvel Mystery Oil - I don't think that does much, but just in case...).

It didn't change anything. It appears to be only coming from the driver side.

So now I think I might have to check or replace the lifters. On the old slant 6 ('83 hydraulic lifter engine) I replaced the lifters and that was pretty straight forward, but I've never done that on a small block. On the slant 6 I replaced all the lifters, but I'd prefer only to replace the bad ones this time.

How do you tell which ones are bad? Is there a way to test them once they are out of the engine?