search in the forums, i don't know if there is a how-to yet, but i found where to port my upper intake in 5.0 mustangs and super fords mag. they were showing where a company ported the plenum.
Honestly its really not worth porting the stock throttle body. You arent even really notice a differece at all either. personally i would just look into the accufab 70mm throttle body and also a c&l mass air. With doin those simple bolt ons you will smooth out the power across the band and will equal fast et's. good luck bro and let me know how you do.