I need to know do I have the correct fuel pump? The engine is a 72 455. When I look at the assembly manual it shows the bigger hose going to the main fuel line. Since I have two lines coming from the rear from the gas tank, I was thinking one of the line was the return line, but one of the fuel lines show that it should connect to the cannister located on the core support. The car when I got it, came with an after market electic fuel pump that some decided to put on it and I removed it. The other line that was coming from the rear was connected to the cannister in the picture.The assembly manual calls this line an emissions line. Now I do have to replace this cannister since one of the plastic inlets(outlet) is broken. Am I on the right track here thinking this is indeed an emissions line?

 

 

What is the year and model of the car? The fuel return pumps were used on A/C and hi perf engines. If you car did not have either of these originally, it is not configured for fuel return. From the pictures, I'd say it is not. You can either replace the pump or cap the fuel return line.

 

Thanks Joe,

The car is 72 442 that originally came with a 350. Somewhere someone put a 72 455 in it. It has Ga heads.The car is equiped with ac. Do I gain better performance by adding a return line? Also can you tell me what is the purpose of the cannister?I looked in the manual and saw how it is connected. It refers to that line as the "Emissions Pipe"

 

My question is why is the 455 painted GOLD,
it should be blue! Sorry, I am just "Nitpicking".

There is no "performance gain" by running a return line,
However on an a/c'ed car the return line is to allow the fuel to return
(or simply getaway) from the hot intake manifold when the engine is off, therby helping to eliminate VAPOR LOCK.

JLK
1971 Cutlass Supreme Convertible
455 Tri-Power
4-Speed
3.73 W/G80 & W-27

 

The Vapor Cannister is to catch the vapors from the fuel bowl,
(during a "Hot-Soak" situation) and condense them back to liquid fuel,
and return them to the tank! JLK

 

According to the 72 service manuals, the 350 A bodies do not use fuel return. The 455s in A bodies do.

The "emission pipe" is the vent tube running from the standpipe vent assy behind the rear seat to the center inlet of the charcoal can. The other side of the charcoal can goes to the carb so the stored vapors can be burned.

The fuel return pipe goes from the fuel pump to the fuel tank through another connection at the sending unit on top.

I do not know the exact purpose (other than possible vapor lock issues) of the fuel return setup, just telling how it is hooked up.
The non return pump has an internal bleed valve to relieve pressure to carb when engine is shut off.
My 350 w/AC has no return and the pump has only the two connections.

You can try using the 350 2 connection pump and see how it works. Adding the return line and new tank sending unit can get complex, unless the car is all disassembled for resto.

 

I painted it gold is because that is the color it was when I got it. There was no evidence on the block or heads that it had ever been blue.

 

I thought it may have been personal preferance, I just couldn't resist asking. JLK

 

I never knew that blue was the color that the 455 were. Good information to know. I plan on capping the return line on the fuel pump as Joe suggested vs buying another new one.I also need to fix this charcoal cannister so I will working on that. I really want to have this car as close to correct as possible,but I dont plan on putting it in any shows even though I have basically done a complete restoration. I am building this car to drive it when I get ready to. After all the work I have put into it,hopefully I will be cruising it around town. My wife teases me all the time and says she wants us to be able to drive it this summer to Chicago. I dont know about that just yet but looking forward to it.Thanks everyone for your help I am sure I will have other questions before I finish,but it is getting close

 

If the engine parts were hot tanked at some time in the past, all the original paint would have come off. 455s were red for 1968-69, metallic blue for 1970-74, and corporate blue for 1975-76.