A couple of years ago, I had the tech article that Steve Dulcich published in Mopar Muscle Mag. on Porting Magnum Heads.
Not Magnum RT heads, Edlebrock heads or W-2's  Only stock magnum heads.  I know that the article existed, However, it is one of the mags that accidently got destroyed.  I have had no success pulling up the tech article / archive on the web
 

Without knowing which issue it's hard for us to pull an article out of the archives.

To order back issues look in the masthead of the magazine in the "backissues" section for a phone number and email address for ordering back issues.  

what was it you were looking to know about porting magnum heads?  

everthing,I have the templates.  

This is a basic premise I follow for basic "home porting";

1) Clean up/polish/raise the roof of the port and leave the floor alone. Spending time on the roof gives great benefit, while spending time on the floor of the port does not.
2) Be careful when removing the pinch point where the push rod buldge comes through the port. Removing metal here gives serious improvements, but grind too much, and you'll need to epoxy the hole you made.
3) When looking into the port from the valve side, smooth/blend/taper the protruding valve guide casting. Don't make it flush with the roof of the port, but look at it this way; you're trying to make air flow around it, so "streamline it"

Remember, this is just basic stuff. You can get a lot deeper into it, but a little experience is recommended before you do.  

dont forget the valve guide trick in the pushrod hole