C1 Fuel Pump counterfeit detection

[Arthur T.]

Hi all,

Its a shame we have to have a thread like this, but such is that state of our hobby.

I am shopping for a rebuilt AC - Delco 4663 fuel pump. My car had its original pump replaced with a mid 60's vintage AC 4701 pump, most probably around 1965.

I have seen a couple of these pumps for sale and there are enough differences between the ones I have seen and the 4701 I have plus the 4656s I have seen to raise questions about their authenticity. What I am concerned about is a re-stamp, a form of counterfeiting.

Does anyone have any photos of what a genuine 4663 fuel pump top casting and number stamp look like? I think the pump lower body casting is the same as the 4656 and 4701 lower body.


Art T.

[William C.]

Re: C1 Fuel Pump counterfeit detection

I read your post, and the number sounded familiar, I did a search of my shop and found one in the bottom of a drawer. Don't know where It came from since I don't own any cars that use it, but appears untouched, if somewhat dirty, pictures attached, I could only load 4, I have more so drop me an email and I'll send them directly. The TDB Board seems to be rebelling at me for some reason. You can reach me at "wclupper@neo.rr.com"

[Arthur T.]

Re: C1 Fuel Pump counterfeit detection

The AC 4663 pump is unique to the 1958 250 hp fuelie. No other Corvette uses this particular fuel pump.

[William C.]

Re: C1 Fuel Pump counterfeit detection

Interesting! My First Corvette was originally a regal Turquoise 283/250, (3speed), original no radio car! Nassau Blue with 327/365 4-speed and Sears radio by the time I got it in '66.

[Arthur T.]

Re: C1 Fuel Pump counterfeit detection

looking over the pump closely, I see the AC marking where I expected to find them. I also see the mold parting line on the flange I expected to see with the '4663' number stamped into it. The top body casting has round reinforcements for all the screw holes. That too, I expected to see.

The suspected re-stamps I have seen have had two square crew reinforcements, and the flange was smooth, no mold parting line.

I am surprised to see the fuel inlet / outlet fittings are at right angle instead of 180 degrees apart. Other 4663 parts I have seen were 180. The 4656 pump has right angle fuel ports and it was this feature that distinguished the two.

Is it possible some parts were manufactured as '4663' pumps with 4656 center bodies? Manufacturing in 1958 was not always a precision operation.

[William C.]

Re: C1 Fuel Pump counterfeit detection

Not likely, more probable that it went thru a rebuilder sometime in the last 60+ years and got a set of mismatched parts. The bottoms are interchangible, I have them on the 40083 pumps in my '65, but I don't know if the ones on the 40083 and 4663 are identical.

[Arthur T.]

Re: C1 Fuel Pump counterfeit detection

That explanation works, too. I wasn't sure how long you had the part or what its provenance was. If the pump has ever been rebuilt, your explanation is the more likely.

I also think the question of how to recognize a re-stamped 4663 has been resolved, at least for me. Thanks for your help.


Art T.

[David L.]

Re: C1 Fuel Pump counterfeit detection

Art, I have collected and studied AC fuel pumps for about 30 years but I do not have a 4663 pump. I have had several NOS 4657 pumps, many used original AC pumps, and some rebuilt AC pumps. The rebuilt AC pumps have parts that may or may not be correct with the stamped number. The early AC pumps have a mold parting line on the flange as you mentioned previously. Starting sometime in late 1964 the AC pumps had 2 letters added to the 4-digit partial AC part number which are a date code (examples: "4657 LD" where "LD" = Dec. 1964 and "4657 BF" where "BF" = Feb. 1966). The 4657, 4432, 4665, 4656, and 6559 AC pumps have fuel ports spaced at 72 degrees according to the instruction sheet that is included with NOS 4657 pumps. The 4657 pump can be converted into a 4432, 4665, 4656, or 6559 pump by simply removing the 10 screws, rotating the center section to the appropriate location, and reinstalling the 10 screws. The 10 screws are spaced equally around the perimeter with an angular spacing of 36 degrees. The 40083 AC pump has fuel ports spaced at 180 degrees. I only have two AC pumps (the type with the 10 screws) left in my collection, type 4665, GM # 5621671, that were used on certain 1958-1966 Chev. trucks according to my many vintage Chev. parts catalogs. 1. A used (but rebuilt) AC pump stamped "4665" with "68" casting and 4 radial hash marks (April 1968) in the hole above the outlet port, 72 degree spacing. The part stamped "4665" on the flange was made in early 1964 or prior but not in 1958. Each of the 10 screws has an extremely small letter "S". 2. A used over the counter AC pump stamped "4665 AL" ("AL" = Jan. 1972) with "72" casting and 9 radial hash marks (Sept. 1972) in the hole above the outlet port, 72 degree spacing. Extremely small letter "S" on all 10 screws. Each of my two 4665 pumps have two "frog legs". Looking on the top there are 7 screws the go through 5/16" dia. round bosses and 2 screws that go through a boss shaped almost like a rectangle about 9/16" to 5/8" wide by 1/2". I believe that the "frog legs" were added sometime in 1963 to the AC pumps. Bill's pump does not have "frog legs". I would guess that the 4663 pump is the same as the 4665 pump except for the center section (180 degree port spacing for the 4663 and 72 degree port spacing for the 4665). I do not know when the mold parting line "disappeared" from the flanges on the AC pumps. Dave

[Arthur T.]

Re: C1 Fuel Pump counterfeit detection

Dave,

That was a terrific bit of information. Thanks for taking the time to share it!.

Art