Long valves on W2's with .600 lift?

.550 lift - .018 lash - whatever you lose from pushrod geometry doesn’t leave you with alot.
I would go .650+ so that the valves spend more time at .600 which is where your power is made.

I'll likely usethe biggest pushrods I can fit so I won't lose much from flex. Remember these heads have offset rockers which removes most of the monkey motion Ma Mopar put into her small block valvetrain.

The other issue with a .650 lift is finding the correct springs that I want to use. My Crowers that were on this will go to .650 I believe but I want to go to a beehive or conical spring... lighter rate and better spring control at speed. I still have to work out exactly what I want. Thinking of PAC 1218X's.