New Magnum heads for 347 with Flow data

Here is where some may find this very interesting. I know that some porting info you may run across tells you to concentrate on the bowl and valve job for maximum gains and to leave the pushrod pinch intake flange area alone. Well we already know that it is abysmally small at the pinch and when it's this narrow you can bet that the air is being accelerated to a very high speed here. The air will not be able to make the turn past the S.S. and head down past the valve at such high speeds. So I know from past experience that it is very important to gain some real-estate here on Magnum heads.

As you can see from the pic-I used the end of a 12mm wrench which measures .735" across as a guide and visual aid . The port was less than .690" here at the roof to start with. You can see that I really did not remove much at all.

So how did it impact the flow?

.1 63.3
.2 130
.3 185.3
.4 206.5
.45 199
.5 199
.6 199

The port still stalls but it is important to note that it sounded much better than previous tests above .400" J.Rob