when it comes to head porting, anything thats realy worth the effort is worth taking to a shop that knows their shit
my DIY porting tasks:
-remove casting lines
-smooth port walls of the sand cast surface, no farther
-port match
-very conservative removal of valve shrouding
-trim the sharp edges in the combustion chanbers to elim hotspots
after that, porting becomes a black art, charge velocity has to be kept as uniform as possible from the top to bottom of the port, and the valve bowl area is very easy to fuck up
its more cost effecive to get a second job w/ your time and pay someplace like jancen / oddy’s / hybrid to do it then to go try it yourself and waste alot of free time
and youll get way better gains too
not to discourage you tho, not trying to sound negative