Help with Valvesprings and valve float. Noob

Just to be clear, I wasn’t having any problems with that particular SB.
I didn’t build the motor.
The owner wanted it rev higher than the 5100rpm he could get out of it.
I told him my fix would be to replace the hyd cam with a SFT, and the problem would go away....... which it did(a scenario that has played out multiple times).
That motor sounded as happy as could be at 6800 with the little solid cam in it.
I made a few pulls to 7k, and it was just barely getting into some instability at that point(although you couldn’t hear it yet).
Springs set up at 130/330.

As for the lifter collapse/pump up thing......I’m tired of arguing about it.
I’ve tested it enough, on multiple platforms to be comfortable with my conclusions.
When you have the hyd lifters set up with lash......... and the motor runs into the wall at rpm...... it’s not from “pump up”....... because they can’t.
And when you swap them out for solids, with no other changes, and gain another 1000rpm+........ it’s pretty easy to figure out what the weak link in the system is.

I had a 383 show up several years ago, pretty much the same story.
Had a Hughes hyd cam in it, ported 346 heads, 1.6 rockers.
They did the heads, had their springs and rockers on it.
Ran into the wall at 5500.

I told him the same thing....... just put a solid in it and the problem will be gone.

Installed a nice street solid in it and upgraded to a suitable spring for the cam/rockers ........ peak hp at 6600.
I ran it up to 7200 for a few pulls, but it hadn’t nosed over at that point yet.
Stock rods...... so I didn’t take it any higher.