I took some pics of the parts as I was tidying up.
1, 1/4-20 hole tapped in plug.
2, 1/4" UNC bolt showing length of bolt.
3, socket in place as something for the bolt to pull against. Plug fits inside socket.
I have ground lots of cranks in my life. You must remove the plugs to proper clean the sludge. Most old stuff that ran non detergent oil the plugs hid lots of sludge. 4.2 Jag engine hade a big plug about 3/4'' every one that I removed had a nickel size plug of grindings and sludge. Also when you get the crank back from the shop run a brush and clean solvent through the passage ways some shops do not clean after grinding.
