Help with Valvesprings and valve float. Noob

BTDT on those so-called 'hardened' shafts and needle bearings. Same result in 1000 miles and never any high RPM's nor anything like valve float and just moderate springs (the Edelbrock heads' standard flat tappet springs). So, the cause is 99% likely just crappy shafts and high point loading from those cheap needle bearing assemblies. The needles are too few and too far spread out for this loading, and if you read up on this type of use, the mfr's of bearings will tell you that this type of reciprocating use is the most severe use for needles as it tends to push all the oil out of the contact area.

Time to junk those; mine were PRW PQ's and yours look the same. I'm converting my PQ rockers to have 2 bronze ring bushings rather than those cheap needle bearing assemblies. I'll try those on another engine.

Meanwhile, the original engine on which these failed in the same fashion as yours got a get of Hughes rockers... solid bore aluminum rockers.