69 fuel line question

[Brad H.]

Everyone,
I have a 69 350/300 that has had the A.I.R removed. I have restored the engine and engine compartment but at this time I am electing to delay adding the A.I.R system back to the engine. As you know the original 69 fuel lines from the fuel pump to the carb were made up of 3 lines. The 3/8" lines were connected to an inline fuel filter which was attached to the A.I.R. pump. If you simply use the prebent lines for this application the inline filter sticks up in the front of the engine by itself because there is no pump bracket to attach it to. The parts books show the fuel pump for my engine to be the same for 69-72. So this is the question: Does anyone know if on the later cars (70-72) where the A.I.R. system was not used, if the fuel line would fit a 69 350 as a one piece line direct from the Q-jet to the fuel pump? I was hoping someone might know, as bending this line is pretty tough from scratch and I hate to just order prebent lines just hoping for a fit. If so, which year would be the best to try ordering a fuel line for?
Thanks for any input you may have,
Brad Hood

[Phil D.]

Re: 69 fuel line question

Not if you have your original fuel pump. I have a 69 and a 72 in the garage right now and just looked at both of them. The 69 fuel pump has in inlet and outlet only with the return coming off the external filter. The 72 pump has inlet, outlet and return fittings and is somewhat larger dimensionally. Also, the 72 pressure side to the carb comes out towards the rear of the motor, has an elbow fitting that the steel line attaches to. The 69 pressure side comes out toward the front of the motor and has no elbow. While catalogs may call for the later style pump as a "universal" replacement, the originals were set up very differently.

[Joe L.]

Re: 69 fuel line question

Everyone,
I have a 69 350/300 that has had the A.I.R removed. I have restored the engine and engine compartment but at this time I am electing to delay adding the A.I.R system back to the engine. As you know the original 69 fuel lines from the fuel pump to the carb were made up of 3 lines. The 3/8" lines were connected to an inline fuel filter which was attached to the A.I.R. pump. If you simply use the prebent lines for this application the inline filter sticks up in the front of the engine by itself because there is no pump bracket to attach it to. The parts books show the fuel pump for my engine to be the same for 69-72. So this is the question: Does anyone know if on the later cars (70-72) where the A.I.R. system was not used, if the fuel line would fit a 69 350 as a one piece line direct from the Q-jet to the fuel pump? I was hoping someone might know, as bending this line is pretty tough from scratch and I hate to just order prebent lines just hoping for a fit. If so, which year would be the best to try ordering a fuel line for?
Thanks for any input you may have,
Brad Hood

Brad-----

You've thought this one through pretty well but there's one flaw in the information you're basing it all on. All of the Corvette small block fuel pumps were not the same from 1969 through 1972. The 1968 and 1969 small block fuel pumps were the same (AC 40658). However, both of these years used AIR for all engines and the same fuel line configuration.

For 1970 and later, most Corvette fuel pumps changed to the "long canister" style (AC 40769). Also, the in-line fuel filter was eliminated. For these applications, the fuel return line originates at the fuel pump. The configuration of the long canister style fuel pumps is enough different that you cannot use a 70+ pump-to-carb fuel line with a 68-69 fuel pump even if you are willing to forego the inline filter.

The exception as far as long canister fuel pumps for 70-72 was LT-1. These applications used fuel pumps that although different than the 68-69 style are fully interchangeable with the 68-69 style pump. In fact, the 70-72 LT-1 fuel pumps were used as a SERVICE replacement for 68-69 small blocks for many years. There is a difference in configuration on the INLET side, but this does not affect the outlet and pump-to-carb line.

The problem is that the 70-72 LT-1 used no in-line fuel filter AND, more important, the configuration of the pump-to-carb fuel line is designed for a Holley carb with high rise manifold and will not work for a Q-Jet.

The bottom line is there is NO 1970 or later Corvette small block pump-to-carb fuel line that will work for a 1968-69 small block.

So, can one obtain a pre-bent pump-to-carb fuel line that will work with 68-69 which has had the AIR system removed? It may be possible. I believe that there may be a NON-Corvette fuel line that will work. During the 68-69 period, many Chevrolets with automatic transmissions did not use AIR. Many used Q-Jet carburetors and the same intake manifolds as Corvette. A few, such as 1969 Camaro and 1970 Nova with 350 cid engines also used the GF-432 fuel filter. The problem is I don't know if these applications used a fuel pump with the same outlet orientation as Corvette. However, all that would require changing is the fuel pump to the Camaro or Nova pump which should work perfectly on a Corvette.

[Brad H.]

Re: 69 fuel line question

Thanks very much for that great information. I had been operating under the assumption obviously that the pumps were the same. I think its time to break out the tubing bender. I really appreciate the help with this!
Brad Hood