Questions on AC 40658 fuel pump

[Joe L.]

Re: Questions on AC 40658 fuel pump

I believe it's AC-Delco #40503.

John------


The AC 40503 was used for 1967 Corvettes. However, I am not aware that it has been cataloged for 1968-69 Corvette small blocks although it could very well be. Assuming that the outlet fitting is in the same location as the 40658/40709 it ought to work fine.

[Paul S.]

Re: Questions on AC 40658 fuel pump

Thanks again, guys -- I really appreciate the help!

One last question (sorry)... if I can find a NOS or original used 40658 fuel pump with the correct AC logo, is there anybody you know of that rebuilds them with all new internal components? I know these pumps were not originally considered "rebuildable", but I found some threads on the Corvette forum that suggest they can be rebuilt.

I assume going this route would really be the only way to have a fully "safe" 40658 pump with the correct AC logo.


- Paul

[Joe L.]

Re: Questions on AC 40658 fuel pump

Thanks again, guys -- I really appreciate the help!

One last question (sorry)... if I can find a NOS or original used 40658 fuel pump with the correct AC logo, is there anybody you know of that rebuilds them with all new internal components? I know these pumps were not originally considered "rebuildable", but I found some threads on the Corvette forum that suggest they can be rebuilt.

I assume going this route would really be the only way to have a fully "safe" 40658 pump with the correct AC logo.


- Paul

Paul-------


I'm not really a fan of rebuilding these pumps. You do get the improved rubber components but, at the same time, you get the downside of a pump that was not intended to be rebuilt and the various compromises that go with that. The biggest compromise, in my opinion, is the "un-crimping and re-crimping" of the bottom section of the pump. I understandt, though, that some of the rebuilders use NEW bottom sections. Still, they are crimped in what amounts to a "field repair".

The only outfit I know of that does this rebuilding is Paul Baker at Goat Hill Classics who has done this for many years. But, I think there may be other rebuilders now. Understand that I am not endorsing Paul and/or the rebuilding of these pumps

[Paul S.]

Re: Questions on AC 40658 fuel pump

Thanks again for all the help, Joe -- I really appreciate it!

If anyone else knows of any other places that rebuild these pumps or has had any experience with doing so that they can share, please let me know!


- Paul

[Joe L.]

Re: Questions on AC 40658 fuel pump

I believe it's AC-Delco #40503.

John------


Can you tell me if the 40503 has officially superseded the 40658 or 40709 in the GM parts system?

[John D.]

Re: Questions on AC 40658 fuel pump

joe
When I look up the fuel pump for 69 in the GM catalog it shows p/n 06416741 which is not available but it shows it cross references to AC Delco 40482.

[Joe L.]

Re: Questions on AC 40658 fuel pump

joe
When I look up the fuel pump for 69 in the GM catalog it shows p/n 06416741 which is not available but it shows it cross references to AC Delco 40482.

John-------

This is the 1967-69 big block fuel pump. As far as I know, AC 40482 is the AC Delco part number for the pump also known as GM #6416741.

The 40658 was the original pump used for 1968-69 Corvette small blocks. It was once available in SERVICE under GM #6417337 but was discontinued from the GM parts system many years ago. The AC 40658 soldiered on in the Delco parts system for many years. It was eventually replaced by the 40709 which was the original pump used for 1970-71 LT-1. The 40709 is also now discontinued.

The 40503 was the small block pump used for 1967 Corvette small blocks. As far as I can tell, the only visual difference between this pump and the 40658 is the angularity of the inlet nipple. So, I could understand if the 40503 was used as a SERVICE replacement for the 1968-69 Corvette applications but I have no information that as far as GM goes, the 40503 ever superseded the 40658 or 40709.

There is one other possibility that might prevent GM from replacing the 40658 with the 40503. The 40503 was originally used with Holley carburetors. The 40658 was used with Q-Jets. So, there may be some internal difference between these pumps because of the different carburetors they were used with. However, the 40709 was originally used only with Holley carburetors but became the SERVICE replacement for the 40658 which was originally used only for Q-Jet applications.

[Jim T.]

Re: Questions on AC 40658 fuel pump

Paul Shatlock I have a 40658 pump from my 1968 Corvette that was installed by me in July 1975. It has the AC indentification like Joe L. pictures. It has a stamping of 292M40658. If you are interested in this pump e-mail me.

[Edward C.]

Re: Questions on AC 40658 fuel pump

I believe the IG is the date code. The I is the month (September) and the G is the year (1967)