I had the Pro Flo system on a 427 big block and it ran great with RPM heads and cam. As long is the chip calibration is correct for the camshaft, it's not a bad system. My experience has been as long as you don't exceed
[email protected] duration on the cam, the original Pro Flo setup works quite well. The Pro Flo 2 upgrade eliminates the need for the chip but still requires calibration files and I don't think it gives you any more headroom on the camshaft. You really need 10-12" vacuum to make the Pro Flo work. Given the cost of the upgrade, I agree it's a tough call whether to upgrade or just buy or more flexible EFI system.