AC 4656 Fuel Pump or Not?

[Joe M.]

Please take a look at the 4 photos and let me know what you think. Here are the details of this pump that do not appear to be common to the original 4656.

1) The long flat bossed area opposite the pump arm is incorrect, should be one boss per screw
2) Two vent holes on one side of arm tower, should be one hole on each side of the arm tower
3) Lack of dipped out places on each side of the arm tower to make it easier to insert the bolt and/or socket.
4) There is a flat place where the arm tower transitions to the flared out part of the pump body; original had smooth transition

Photo #4 has me baffled. The flange where the 4656 is stamped looks original; no evidence of grinding, the parting line is intact across the flange and the 4656 is stamped across the parting line. Please share your opinions on this pump .

[John F.]

Re: AC 4656 Fuel Pump or Not?

I don't think hand stamping was an exact science on any GM parts!

[Joe M.]

Re: AC 4656 Fuel Pump or Not?

Based on the photos, is this pump a "correct" 4656 for my 1960?

"4656" stamping on mounting flange look original and untouched?

I suppose that will be up to the 1958 - 1960 judge, but I want to purchase a pump that represents what they are looking for or as close as I can get without spending $300.

[Brady C.]

Re: AC 4656 Fuel Pump or Not?

Joe:

My 58 has the same markings for the part number and from your pictures, looks to be correct from the AC 4656 pump i have.

Tks,
B. Como
#42793

[Mike E.]

Re: AC 4656 Fuel Pump or Not?

Doesn't look like a typical stamping to me, nor does the double hole in the body look typical. I wouldn't pay that kind of money for that pump.

[Joe M.]

Re: AC 4656 Fuel Pump or Not?

i agree with you Mike. I believe the correct configuration is one vent hole on each side of the pump arm "tower."

Was the 4656 fuel pump used on any other GM products during 1958 - 1962? If not, I will stop calling classic car salvage yards.

Attached are a couple of photos of a pump from a 1960 that I believe confirms some of the attributes of the 4656.

Now that I know what to look for, probably not willing to pay $$$ to buy a correct 4656, but I am going to keep looking. I located one for $300, but too expensive to put on my driver car. The point deduction I will receive at the Lone Star Regional for using my 4657 pump will be a minor part of the 1,000s of points I will lose anyway; just want to have it judged for fun.

[Loren S.]

Re: AC 4656 Fuel Pump or Not?

Joe, your stamping looks like the stamping on the 4656 pump Zip sells for $129:

http://www.zip-corvette.com/ProductD...=SGR-SR&CTitle=&

For comparison, here are some photos I saved of a 4656 pump which sold for over $300 on ebay a couple of years ago:

[Joe M.]

Re: AC 4656 Fuel Pump or Not?

Thanks for the excellent photos Loren. The high cost will prohibit me from purchasing a $300 pump. CC sells "correct" 4656 pumps when they can get them for $124. I will not purchase a pump from anyone until they send photos to document what the pump looks like.

[Mike E.]

Re: AC 4656 Fuel Pump or Not?

Loren's pics are typical of what I've seen over the past 35 years on original pumps.