New Magnum heads for 347 with Flow data

Past experience has taught me to consider the chamber when flow stability is problematic. I put a spare valve in the guide and carefully blended and tried to remove anything abrupt around the perimeter of the valve seat--especially the sparkplug boss. You can see that it was worth some flow but 'nill in stability. J.Rob

.1 63
.2 126.5
.3 191
.4 223
.45 215
.5 215
.6 215