Freeze plugs for 65 289 question

[Shane]

I am more acquainted with the "1-1/2" stamped version that Charles mentioned, although as previously discussed, the paint and position often obscure such details. Nonetheless, I would be interested in hearing further thoughts on those variations in stamping.

[J_Speegle]

I saw one other variation of a diamond with "1 1/2" inside the diamond, but guessing these were aftermarket replacements.  They were the right shape/design though.

+1 Typical of replacements you could buy through the years at any auto shop.