Hey are you gonna run .620? or .580 lift? how about .550 lift?
They flowed great with the valves that came with them, MAD DART is doing WAY MORE than you are, so don't confuse this.
Besides... A set of .100+ 2.020/1.60 chev valves cost a whole $120 and opening the guides and VJ on int's would only cost another $245 and heck you could breath on these RHS's with a grinder and have bitchin #'s.
Read all of the thread/s 1st.