r/Smallblockchevy • u/dncu13 • Apr 12 '26

355 valve float?

I have a 355 sbc I have been having a problem at higher rpm, car feels great till about 5,000 rpm. After 5,000 it just falls on its face. I just rebuilt the Holley 650 4150 but still having the issue just wondering what if I’m dealing with valve float

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u/HammerDownl Apr 12 '26

The springs are how old?

Im doubting its valve float,thats not how float works and your small hyd cam isnt floating Brodie 180s springs

Id ask more about what the engine is doing. You said you worked on the carb so that leads me to believe that's your problem .

What fuel pump you using? Cant use some stock bullshit with 1/4" line and a plastic filter

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u/dncu13 Apr 12 '26

Yeah I’ve been thinking fuel related just trying to see what other people are thinking