I found my Delco Remy manual, and it turns out they are polarity sensitive (at least my series of regulator is). Apparently it’s pretty easy to tell, it’s stamped right on the base of the regulator. See attachments.
Now I’m left with either trying to find a positive ground fuel gauge, or funding a Chevy negative ground regulator and swapping the entire truck to negative ground. I’m sure the Chevy regulators are easy to come by, but I really didn’t want to go that route.
