New Magnum heads for 347 with Flow data

I flowed them on a 4" bore as they came out of the box using a reconditioned set of valves that came out of a set of cracked Magnums.

All testing is done at 28" of H2o

Intake Exh
.1 58 53
.2 115 102
.3 165 135
.4 192.2 135
.45 193 136
.5 193 136
.6 188 137

The stock valve job was very small .040" from the edge of the valve and the throat percentage came in at 84.6% of 1.92"

As you can see the numbers are on par with a stock set of Magnums.