Here are my numbers, a result of DYI home porting job using the MP SwirlHead porting templates:

596 castings, I had the machine shop go over them, they put in new Manley severe duty valves, 2.02/1.60, 11/32 stem, new bronze guides, and a standard 3 angle valve job. I ported them using the MP porting templates, here are the flow numbers (flowed on SF-600 @ 28" water):

LIFT I E

0.100 67 57
0.150 99 79
0.200 130 104
0.250 162 125
0.300 189 140
0.350 215 152
0.400 235 160
0.450 253 167
0.500 262 172
0.550 261 175
0.600 248 177