Oil-galleries- how to clean

[CLKWRK]

I use brass NPT plugs but you can get aluminum ones (avoid steel plugs, different expansion rate as AL), you can just run the tap without reaming it as the cast material is extremely soft. Careful how deep you run the taper tap in as your plug might partialy block an oil passage.
I use regular teflon tape to seal it up, had no problems doing it that way for the last 12 years.

Once off, I use varisol, power washer, detergent and rifle brushes to clean the bores out

Bry