Picked up a PSL-54c

[highpower3006]

Make sure I'm understanding this correctly, your tapping the port in the gasblock itself, so if you decide you don't like the port mod plugs (for lack of a better term) and take them out, your just left with a threaded port, right?

Correct.

I was a bit nervous when I first went to tap my gas block. The trick is to buy a new American made tap that has at least three (four is better) flutes. Use real tapping fluid and go slowly. Mine went very easy and I had no trouble at all tapping the hole to the proper depth. If you use a new (sharp) quality tap and a small tap handle and back off the tap every half turn or so, you should have no problems at all. Most of the taps that I have seen break, failed because the person doing it was using too big a tap handle to drive the tap and twisting too hard.

I think that once you tap the hole, it would be even more oversize than it already is, so I would say the best thing is once you find the size of port the rifle likes, and .060-.065 seems to be the optimum size, just resist the urge to tinker further and leave it alone.

I would stay away from using inferior taps and avoid anything made in China. I bought two taps, a can of tapping fluid and a box of set screws for around $35 shipped from MSC. I now have three lifetimes worth of screws, but they are small and don't take up much room. The up side is that I have found other uses for a few so I was glad I bought extras.