Mid-year in-tank fuel sending unit

[Gary B.]

Several weeks ago my chassis co-judge easily was able to tell that several mid-year cars we judged did not have the correct fuel-tank sending units. I didn't get remember to ask him how he detected the incorrect part, but I'm wondering now what I should puchase for the restoration of my '66. I believe the current AC Delco part is 6428065. Is this the best part to buy in terms of a current replacement and is this current item apt to get the few or no points deduct?

Thanks,

Gary

[Philip C.]

Re: Mid-year in-tank fuel sending unit

Hi Gary The easiest way is to remove the gas cap and look at the sending unit.There is a big difference between replacement ones and the original ones. The flare on the fuel line is another way its much larger and you can see the bulge in the rubber line. Phil 8063

[Gerard F.]

The difference is in the terminal nuts

and studs.


Gary,

The picture shows a cheap foreign made sender next to my 67 original. The original has threaded terminal studs and zinc plated nuts. The foreign jobber has unthreaded studs and a pressed-on insulator which cannot be tightened.

However the 6428065 may or may not have the zinc plated terminal nuts but I think would have the threaded studs. Here's a GM replacement (or an earlier then 67) in a 1984 box:


It has threaded studs but off-white neoprene or hard plastic nuts on the terminals. Don't know if the unit is the part number or an earlier original as it came to me in an opened 1984 box labelled "Defective Vette". It has "AC" on the bottom and "Made in USA" between the I and S terminals

It is defective as the ohms are off but I think it will be easily fixable with just cleaning the contacts. When I get around to fixing this one, and replacing my repaired original on the car, I'm just going to use the original nuts and insulators on this one.

Not sure if anyone would notice the difference in nut type on the GM sender, but the yellow press-on insulators on the foreign jobbers are very noticeable, and you wouldn't have the "Made in USA"

Jerry Fuccillo
#42179

[Joe R.]

Re: Mid-year in-tank fuel sending unit

Hi Gary:

When viewing the sender from underneath the car, I believe an original sender will have the large letters "I" and "S" plus "AC DELCO MADE IN U.S.A." as shown in the photo below. I have heard that some judges will make a deduction if these markings are not present.

The current GM replacement part does NOT have the AC Delco marking, and if I recall correctly it does not have the big letters "I" and "S" either.

[Gary B.]

Thanks guys. Differences seem clear. *NM*

[Dave K.]

Re: Thanks guys. Differences seem clear.

Gary,

Fortunately for me I was able to repair my original sender for my 66. I looked into replacements and you can still purchase an NOS sender but for about $250. Service replacements are about $100. There were also threads in the archives warning about foreign manuafactured senders that were potentially dangerous and could either short or cause a spark.

Regards,
Dave K.

[Gary B.]

Dave; original vs. NOS differences

Dave,

Yesterday I saw an AC unit with the "AC MADE IN U.S.A." stamping on the bottom, but it didn't have the upper case S and I stampings. This would appear to be one way to tell new/NOS from originals.

Gary