stealth heads vs edelbrock heads

I have recently received three sets of 440 Source Stealth heads. They are now prepping the intake ports as does Edelbrock with the RPM heads, all be it a little more crudely. In the past when I flowed Stealth heads they went

.500.............255 cfm
.600.............267 cfm
.700.............268 cfm

and are now flowing OOTB

.500.............270 cfm
.600.............283 cfm
.700.............290 cfm

Easily enough to produce 500 HP if the engine is prepared properly.

The lower lifts remained the same, but the Stealth heads are now EQUAL in flow, OOTB, to the RPM heads, whereas in years past they were not.

The retainers appear to be of better quality, the locks are still digging into the valve stems and raising sharp edges that will score the bronze guides if the sharp points are not filed off prior to removing the valves.