Smallblock Heads?

yup. W2 econos are a really nice starting point. too bad they discontinued the W5 a few years ago...

heres some W2 flow #'s:

LIFT Intake Exhaust
050 32 24
100 61 55
200 132 115
300 188 170
400 236 197
500 272 209
600 300 213
700 314 215