This is a simple mod for the exhaust port on the 2.3.If you are running a header than you have had to deal with the air port in the floor of the runner exiting out under the flange of the header.I've tried alot of methods and while not the easy one it is the best.You will need a 3/8 16 tap 4 3/8 16 x3 in bolts jb weld,NOT jb quick a hack saw,large flat mill bastard file and a die grinder.
   The first order of business is to run the tap through the hole,no need to drill it out.Next you will need to angle cut the end of the bolt to the angle in the port.Now bung the threads on the bolt to help lock it into place. Mix your JB weld and apply it to the bolt close to the bolt head not on the end of the bolt,and thread it in the hole till the bolt comes through to the port far enough to be able to grind flush with the floor of the runner.Now let the JB dry. Now to finish it up.take a hack saw and cut the bolts off flush with the head,next you will need to take a large flat file and file the bolts flat to the side of the head.Now take a punch and stake the bolt in place,then refile.Now grind the bolt flush with the bottom of the runner and voalia a better flowing port and an exhaust leak point eliminated.I'm not the best at explaining how to do things but I hope with the pictures it will be easy to understand my rantings.

Nice job!  I tapped mine with a taper pipe tap, and screwed in steel recessed allen head set screws - works well but does not fill the hole the way your method does.  I am sure i will re-do mine in your method.
Thanks!