What would this be for

[Mr Goodwrench]

Bought a fuel pump for the 66 impals327 engine, is this vacuum port supposed to be here????

 

[Phil Reed]

I've never seen a guel pump like that.

 

[Fathead Racing]

That is a marine fuel pump. The hose barb connection is a safety feature in case the fuel pump has a ruptured diaphragm you would connect a clear hose to that fitting to route the raw gasoline away from the bilge on your boat. On a car a fuel pump with a ruptured diaphragm the gas would just drip on the ground, in a boat it would drip to the bilge and boom! It will work on your car no problem

 

[Fathead Racing]

Phil, I've never even heard of a guel pump. But I guess that would explain the hose barb fitting

 

[Don Jacks]

You can also use that pump as a "boost reference" pump to increase your fuel pressure to the carb as your boost goes up with a small blower.