4.7L - how to pinpoint a bad lifter?

So I got what sounds like a lifter or two tapping bad ever since it turned "cold" here in ATL. Happened a few days ago and sounded pretty loud on cold start, but went away to nothing as the oil flowed up. Today it kept tapping for a 5 mile drive and was tapping when I pulled up. Parked, came back an hour later and it was perfectly quiet upon starting. These are new Sealed Power lifters I installed around April...sigh. Kinda glad it sounds like the passenger side, cause I had to loosen the brake booster to get the driver's side valve cover off.

Any idea on how to check 4.7 lifters without pulling them all out one by one? I suspect I won't see anything just eyeballing them.

 

Weeks later and the noise hasn't returned. Back to being quiet again even after the car has sat for days in the cold without being driven. Strange issue.

 

SAME ISSUE my motor is brand new rebuilt rings cams cranks pistons heads etc... Less than 3k miles. But it goes away and hasn't came back...

 

Yeah, temps have hit the twenties, here in ATL. Even after sitting undriven for days, there is no valve clatter anymore. Strange issue.