Lifter Not Pumping Up

340, bored 40 over.
J-heads, punched to match X-head valves, and deck lowered to bring static compression up to about 10:1. Ported and polished.
KB hypereutectics.
Lunati 60403 hydraulic flat-tappet camshaft with matching lifter kit.
Set of very old mopar adjustable rockers, clearenced for reasons I still don't quite understand (long pushrods?).
The valve springs appear to be the recommended 1.44 diameter with 1.85 height, 200 lbs at 1/2 inch compressed.
Forged crank probably on its last grind, 40 on the journals, 30 on the mains.