Fuel pump replacement for 365HP '64

[Rod R.]

ACDELCO 40083
https://www.rockauto.com/en/moreinfo.php?pk=451627&cc=1323762&jsn=438&jsn=438


AIRTEX 40083
https://www.rockauto.com/en/moreinfo.php?pk=58776&cc=1323762&jsn=435&jsn=435&j sn=435

SPECTRA PREMIUM SP1227MP
https://www.rockauto.com/en/moreinfo.php?pk=6285645&cc=1323762&jsn=441&jsn=441

[Joe L.]

Re: Fuel pump replacement for 365HP '64

I am replacing my original 40033 fuel pump for my 365 HP ‘64. I am rebuilding the pump and will replace with a new pump for driving. I have three choices for a pump that is close to my 40033. My question is anyone familiar with these listed replacements? Is one better than the other? Will they connect to the original fuel line without modification? The Airtex and Delco pictures look identical. Are they made by the same company?

ACDELCO 40083
https://www.rockauto.com/en/moreinfo.php?pk=451627&cc=1323762&jsn=438&jsn=438


AIRTEX 40083
https://www.rockauto.com/en/moreinfo.php?pk=58776&cc=1323762&jsn=435&jsn=435&j sn=435

SPECTRA PREMIUM SP1227MP
https://www.rockauto.com/en/moreinfo.php?pk=6285645&cc=1323762&jsn=441&jsn=441

Rod-------


Your original fuel pump is not an AC 40033. A 40033 was originally used on Buick V-8 engines. It would not work, at all, on a Chevrolet engine.

Your original pump was an AC type 40083, aka GM #6415325. The current version of that pump is the one you show in your post. I believe that all of the above pumps are likely the same and originate from the same manufacturing source. It's clear that they are not manufactured by the AC Division of GM which manufactured the original pumps since that entity does not exist anymore. Even when it did exist, it had not manufactured mechanical fuel pumps since the 70's.

As far as I know, the above pumps should install without the need for any modifications. Even though they are likely from the same manufacturing source, all things being about equal, I'd probably go with the AC Delco-branded part. No real advantage but it would just "feel better" to me.

[Rod R.]

Re: Fuel pump replacement for 365HP '64

Joe,

Good catch. My fuel pump is in fact a 40083. After a closer examination I could see what I thought was a "3" is a lightly stamped "8". Thanks for your input.

Rod

[Don H.]

Re: Fuel pump replacement for 365HP '64

Rod, other than being dirty, does your pump look like this one?

[Rod R.]

Re: Fuel pump replacement for 365HP '64

Rod, other than being dirty, does your pump look like this one?

Yes Don, it looks like my 40083 pump.

[Jim L.]

Re: Fuel pump replacement for 365HP '64

All three of the pumps appear to be identical. My hunch is that Airtex is the manufacturer of all three. Airtex pumps have a well-deserved reputation for failing due to the pivot pin for the pump lever slipping out of place.

See postings #2 and #10 in the following link to see the problem and one way to prevent it from happening:

https://www.corvetteforum.com/forums/c1-and-c2-corvettes/3855676-fuel-pump-failure.html

Jim

[Rod R.]

Re: Fuel pump replacement for 365HP '64

Jim,

Yes, the pumps do look identical except for the price. The Airtex and Delco are closely priced and the Spectra costs about twice as much as the other two.

Thanks for the link about the problems with these pumps and the fix. Good information.

Rod

[Frank D.]

Re: Fuel pump replacement for 365HP '64

AirTex has been contacted more than once by car owners about the pin walkout problem - the company reps feign interest and then do nothing apparently...

I would rebuild your original pump with a Paragon kit and drive on...

I just did that with the 4657 on my 63 car and picked up another 4657 (too cheaply to pass up) that I will do next week...

[Rod R.]

Re: Fuel pump replacement for 365HP '64

That is what I am doing. I will finish the rebuild tomorrow. I don't want to waste time and money on an after market pump with a history of failure. Thanks for you input.
Rod

[Troy P.]

Re: Fuel pump replacement for 365HP '64

I have a slightly used replacement pump you can have for the cost of shipping. I recently took it off my 63 fuelie to install a correct AC pump.

[Rod R.]

Re: Fuel pump replacement for 365HP '64

I have a slightly used replacement pump you can have for the cost of shipping. I recently took it off my 63 fuelie to install a correct AC pump.

Troy,

Thanks for the kind offer, but I do not need it now as I have rebuilt my original pump. Thanks again.

Rod