Holley carb power valve questions

[Jeff H]

I'm rebuilding a Holley 4557 for my 70 L78 Camaro. It looks like it had a 10.5 primary and an 8.5 secondayr power valve. The rebuild kit looks like it has a pair 6.5 valves? Is that too low to go compared to stock? This carb is really old and has been sitting for years so I'm doing a cleaning and rebuild and can't compare before and after. I'm thinking I need to stick with someting closer to stock instead of the 6.5's that are in the kit.