Ford 289 Valves for /6 - what a deal!

I can tell you there's no way in hell I'd run a spring with 300 pounds open on a 50 year old flat tappet grind. I don't know where that came from. Did Ken Heard tell you that? I'd have a difficult time believing that. Where did you come up with that?

300 open on .479 lift? Seems a bit much.