Engine Ground Location (Lehman)

[rebuckley]

I figured I would post this here. I think (think) I may have a ground issue on my engine block. My guess is that when my transmission work was being done last year they may have removed something and not replaced it, however, I do not even know where to look. While I was working on my starter issue recently, I tried to use the engine as a ground for my multi-meter testing, but was not able to ground on the engine. Instead, I used the ground wires on the starter motor as my ground. After doing this work - I think one of my current issues I am chasing (lack of low oil pressure alarm at start and stop) may be due to the engine block not being grounded? The alarms worked fine last summer - and the only major change was the transmission work I had done. My current assumption is that the alarm dose not have a ground (as the engine is not grounded?) so it is not sounding?
I think the way I could test this is to turn on the key, and jump the ground from the starter to the body of the alarm sender - it should then sound (assuming all else is good)?
Is there a common or typical place where the engine ground is attached on the 120 lehman? This would help me look and see if something is not connected correctly. Thank You .

[Tree]

If I recall when i had this engine or the Ford variation of it a few boats back, there was a large flat webbing like cable that came off the starter and attached to a stud on the engine block