Has anyone ported stock magnum heads and have the before and after flow numbers .???

I'm in no way saying this is a good or bad thing, strictly, oh, look at what I found is this accurate or helpful or what ?. I absolutely do not know enough to say yeah this is great or this is crap. I'm in research mode to select some heads, that's all. I posted here in a questioning mode, looking for all the info I can get on this.
Thanks