So I believe its now pretty common place to replace the early 3 port with a 2 port from the late (75-76) cars.
In addition there are all manner of aftermarket pumps available.
The OE Bosch unit used male spade connectors for the terminals & a printed indicator for which one was hot.
Other units use screw on terminals of a different size, & not necessarily is there any printing on the body to indicate hot.
Is there a convention that suggests that the larger or smaller of the terminals is the hot?

Conventional thinking to me would indicate you would need a larger wire/plug for power and a smaller wire/plug for ground.

Did I mistakenly post this in the Sandbox

Yep. I will move it for you.

Clay

I just made this swap to a Bosch 69133 2-port pump ($59 from Rock Auto) a couple weeks ago. The posts for the ring terminals were clearly marked. IIRC, the positive was the larger terminal, but I can check that later.

FYI, on that particular pump, the inlet nipple is much larger than the 3-port. The 3-port had 7mm(5/16") fittings and on the new pump, a 3/8" hose can barely be stretched on. The outlet is 5/16" so no issues there.