I noticed my hedman oval port headers are not a bad mach for the AFR 195s, but they do hang over the ports by about 1/16" on either side. I'm tempted to port the header flange a little. Is this even worth while? I've got to be losing some flow when the exhaust hits the edge of the header pipe on the way out, right?

I grind mine to fit. I don't know how much it helps, but it makes me feel better. I also extend the primaries about 10", add a small merge collector and an x-pipe.

My Dougs headers did not seem to need this. I am using the Ultraseal 5907 black gasket as the sealing area between two center exhaust ports seems too close for triming. If this was a race motor , I prolly would pay attention to this area.