Tunnel ram or no tunnel ram...
My numbers for RPM heads were:
.100 113
.200 181
.300 240
.400 280
.500 316
.600 328
.700 332
This was included 5 angle valve job and back cut valves. Of course max wedge intake port. I’ve seen 340 at .700 by people so this is nothing impressive. I was thinking about bigger intake but this never happened. I sold them.