Ive been getting a small coolant bubble near the exterior head locating pin on the number 1 cylinder on a stockish 383. I have re gasketed twice with steel shim gaskets. First time with spray sealer which was a noticeable leak. Second time with no sealer and better results with only a tiny coolant bubble. Never enough to even drip. I get the bubble on startup cold or warm, radiator cap on or off no change. I have never over heated it. Stock machined decks and heads So my question is, How close is this locator pin to coolant?

Attached picture shows area of leak but Im not sure if leak is head side or block side.
Im willing to mag and machine just looking for direction on why the leak is in this spot.
Thanks guys.