Like Rob said its for the 302 width motors with a full size dizzy cap. Rail points right to the back of the dizzy cap and cant get a fitting in their so they use that hole. Only way to not use it is a 351 width motor or a small cap setup.
and Ill make him my hood ornament
Edit: would I do it, no but I do get angry when people dont hold up to their end of the bargain.... especially in memory of someone.