Fuel Pump Question
Thread Starter
Racer
Joined: Jul 2004
Posts: 441
Likes: 1
From: Windsor Ontario
Fuel Pump Question
I bought a holley fuel pump for my 1974 Corvette w/350. It has 1 inlet and 1 outlet. My stock fuel pump has 3 lines on it. 1 goes to the carb the other 2 run to the tank. Do I need both these lines going to the tank? Can I use this fuel pump for my car? Thanx
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Most of the later model lower HP Vettes with AC have the return line. And with that, most of the performance Vettes do not. You can successfully use it, but there really isn`t any advantage with the Holley over a stock pump. All of the mechanical pumps are of a lower pressure 4-6 lbs no matter what the original engine is so as not to blow off the needle and seat of the carb. Plus normally the aftermarket performance pumps require a new set of steel lines that may be aggravating to make with out a proper tubing bender. 
Instructor
Joined: Sep 2005
Posts: 185
Likes: 0
From: Buckner Missouri
I found your thread while doing a search for replacing fuel pumps on my '74/350.
Can't answer your question BUT my Chilton says that one line draws fuel from the tank. Another line supplies pressurized fuel to the carb. (and) "Some models use a third line, which is a vapor return. The purpose of the vapor return is to route the hot fuel and fuel vapor from the pump back to the fuel tank, which considerably reduces the chance of vapor lock"
You must be missing the anti-vapor lock line. I just ordered my pump and don't as yet know if it will be 2 or 3 lines.
Good luck.
Can't answer your question BUT my Chilton says that one line draws fuel from the tank. Another line supplies pressurized fuel to the carb. (and) "Some models use a third line, which is a vapor return. The purpose of the vapor return is to route the hot fuel and fuel vapor from the pump back to the fuel tank, which considerably reduces the chance of vapor lock"
You must be missing the anti-vapor lock line. I just ordered my pump and don't as yet know if it will be 2 or 3 lines.
Good luck.
Instructor
Joined: May 2006
Posts: 168
Likes: 0
From: Florence NJ
Originally Posted by toolman0114
I bought a holley fuel pump for my 1974 Corvette w/350. It has 1 inlet and 1 outlet. My stock fuel pump has 3 lines on it. 1 goes to the carb the other 2 run to the tank. Do I need both these lines going to the tank? Can I use this fuel pump for my car? Thanx
If you run the holley pump, just remember to cap off the return line (the smaller of the 2 fuel lines) so you do not have gas vapors in the engine comparment.
I'm changing mine back to a pump with a return line when I get around to it.
