I managed to hurt my engine at last month's autocross. It was a fun run at the end of the day and I was flat out with fairly high RPMs across the finish line when I heard the exhaust note change.
Packed up to go home, made it about a mile or two out of the track before I decided the exhaust note wasn't just off but sounded ragged. Pulled over, popped the hood, heard a fair loud/harsh ticking sound, and parked it to tow it home. Glad I did... The last time I heard a loud ticking noise I ended up with a coffee table sometime thereafter.

So nasty engine tick, what are my possibilities? What I've come up with so far...
-Rod bearing
-Piston wrist pin
-Dropped valve
-Broken valve spring
-Bent pushrod
-Collapsed lifters
Possible diagnosis approaches
-Boroscope down spark plug holes
-Check spark plugs
-Compression check
-Top engine visual inspection
-Oil inspection: change oil... visual inspection, cut open filter, lab analysis (blackstone)
-Bottom end inspection: poking at at stuff can be done with pan pulled engine in car. Plastigage and measuring probably means yanking it.
I decided to start on the top end since it was easy and I didn't want to crank it for a compression check if I might have a valvetrain issues. Valves all look fine but I didn't have to go far before I found 4x collapsed/stuck lifters. Here's the worst one (albeit it stuck this far open after I'd turned the motor over by hand a few times.)

My big question is whether the lifters were the cause or just a symptom of something else. These are Comp Cams "Comp R" lifters. Metal flakes in the oil could certainly jam up some lifters as a byproduct.
Reminder on the engine buildBlock GM LS2 Darton Dry Sleeve
Lunati 4340 Forged Crankshaft (4.00 stroke)
Lunati Billet Connecting Rods
Jesel 1.7 Shaft Mounted Roller Rocker Arms
MTI Stage 3 Hand Ported 243 Cylinder Heads
Wiseco K395X130 forged pistons (11.25:1 compression, 4.130 bore)
Custom Patrick G camshaft (235/239 .602 / .604” / 113 LSA +2)
GM LS9 timing chain
Manton Custom Pushrods - 11/32nds Intake and Exhaust
Comp R hydraulic lifters
PRC .650 dual valve springs
Melling HV oil pump
ARP everything
I bought the engine private party after it had just been freshened by Erik Koenig and HKE. Only thing I didn't like is that the oil pressure has always been a little on the low side. When warm, it idles at about 18 psi rather than the 24 I'm used to. As such I've been running 20w50. Motor's been in the car for, I don't know, maybe 7-8 years at this point? Oil temps peaked about 225 F at the autocross where this happened. I have been having some heat management issues so I typically do a cool down and drive for a mile between passes.
So two big questions:1) Anything obvious I'm missing on my investigative approach? My engine builder options on an island are near non-existent so I'm kinda on on my own.
2) Anything else I should do in car before I yank the motor? I'm hesitant to do any sort of cranking compression check at this point give the collapsed lifters.
Thanks in advance,
Joel