Max lift with stock valve length?

Those are a little lighter than what the comp guy said, and he did say they didn't have anything that would cover it. BUT, I think he was being a little bit over cautious on the upper end of the RPM range I gave him. I doubt these J-heads will be making much power above 6k rpm so I won't need to spend much time there. They may be a viable option. I think I could shim them a bit to increase the load a bit too? They support about .640" lift and I'm not going to use it all.
I shimmed mine within 050 of bind for that little extra pressure, FWIW. So if you can get a 030 locator under then it should put you pretty close to where you want to be with 550 lift.