I tried doing a search but was too drunk to figure out how, anyway here it goes. My buddy has a 94 LT1 with a 6psi procharger unit. He thinks he's hearing detination at around 6k rpm? Changed the plugs to R42 whatever the coldest Ac Delco makes supposebly. Anyway he got a horsepower in a box, and retarded the ignition about 8 degrees and the sound is still there around 6-6,300 rpm. Sounds like detonation! I believe this maybe valve float. Bone Stock LT1 approx 91k miles on deck.
Any replies will be greatly appreciated, thank you for your time Good night!
P.S.
He's about ready to buy an LT1 long Block for about 5k (through the dealer). I said go with the LT1 short block from SDPC for 1,799.00 thanks again!

 

The only way to diagnose with these cars is to have a scanner. This will tell if you have knock and where it occurs with respect to rpm and map.
I don’t see any relation between knock and valve float. Valve float refers to the bouncing of the valve off its seat upon closer due to the inability of the spring to control the mass of the valve at a particular rpm.
I suggest he changes to stiffer springs if he’s going to spin this high, changing an engine to this is a waste of money.

 

stock springs are probably your problem. They will let up very easiy under that kind of rpm with any kind of power being produced.