396 350hp fuel pump

[DeanZ10]

I am not finding a lot of info on the correct part number for this application. Could someone help?
I have seen claims bolted as original, crimped as original, weep holes, no weep holes, some will have dates, some will not.... on and on.

Thanks for any information/clarification

Dean

[HawkX66]

Here is a pic of mine. This one is date coded 1973, which means it was obviously replaced at some point, but it's the correct pump and number. Mine is an L34 like yours. Good luck.

[DeanZ10]

Thanks!   Couple more questions..
How does the date decode? 343=Julian date day of year? K=1973?
Do you know what the 69 code would be?
Also, can anyone tell me if the 69 model was bolted or crimped?

Again, Thank you!

[HawkX66]

You're welcome. Hope this helps. From more reading from the same poster, it looks like "K" might actually be 1971. Mine was a late 69 build, so the pump I have is more than likely a warranty replacement.

From DCL70SS on CRG:
"The first letter is the month, A=Jan, "B"=Feb. ...........................L=Dec. (the letter "I" was used).
The second letter is the year, E=1965, F=1966, G=1967, H=1969.
NOTE: The AC pumps made in 1964 and prior do not have the 2 letter. I have an AC pump stamped only "4657" from a 1964.
Sometime in the early 1970's the date code changed to 3 numbers (the day of the year) and one letter (the year)."

More info from what appears to be the same user that says K is 71

http://www.nastyz28.com/forum/showthread.php?t=207770

[ko-lek-tor]

Thanks!   Couple more questions..
How does the date decode? 343=Julian date day of year? K=1973?
Do you know what the 69 code would be?
Also, can anyone tell me if the 69 model was bolted or crimped?

Again, Thank you!

To answer your question about bolted or crimped. The original pump look just like the picture provided by SgtHawk=crimped. Most GM pumps are crimped, I believe the ZL1 was bolted together and some early  pumps pre-67 and maybe some large truck comercial applications. I am sure someone will tell me different, but forgive my memory on this. The main point is the pump you want will be crimped.
Here is a thread of use and do a search "fuel pump date" and there are other posts. http://www.camaros.org/forum/index.php?topic=11520.0

A side note: SgtHawk I think your pump is for H.P. application, i.e. L78. L34=40568

[mickeystoys69RSSS]

I will try and get the information from mine when I get at chance. It is an original L34.

[ko-lek-tor]

Dating pumps goes like this: 1965 rebuild-able pumps have a part number followed by 2 letters. 1st letter is month,2nd is year.An example would be : 4657KE (Nov. 1965) 1965 ended in E, 66=F
Crimped pumps were phased in around mid-year (June)1966. At this time the 2 letter dating preceded part#(at beginning). An example would be: GF40433 (July 1966) for 67 model year car. 2nd letter is year where: F=1966,G=67',H=68',I=69',J=70'. The months, 1st letter, are A-L=Jan-Dec. Starting in 1971 a new Julian alpha/numeric dating was used. An example :219K40956 (219th day of 1971)This would be for a 1972 car as this is late in the year, but shows that dates follow calendar and not model year. K=1971 remembering this includes 1972 models up to Dec 1971. L=72 and so-forth. Hawks pump is: 343K40727. The 343 is 343rd day of K=1971 (Dec  1971),which is late in year and considered a 1972 pump by model year production.

[Steve Shauger]

I am not finding a lot of info on the correct part number for this application. Could someone help?
I have seen claims bolted as original, crimped as original, weep holes, no weep holes, some will have dates, some will not.... on and on.

Thanks for any information/clarification

Dean

My 69 L34 survivor has its original dated pump. Goathill rebuilt it for me years ago 40568.
   

[HawkX66]

A side note: SgtHawk I think your pump is for H.P. application, i.e. L78. L34=40568

Thanks for that. I had no idea. It goes to show you, anything can happen in 40+ years. I'm not surprised, fuel pumps fail... I'm sure mine was replaced with what was available at the time. Any idea if the fuel pressure is any different between the two? Maybe I SHOULD be thinking about what we talked about in the PM... hmmm.

[Steve Shauger]

A side note: SgtHawk I think your pump is for H.P. application, i.e. L78. L34=40568

Thanks for that. I had no idea. It goes to show you, anything can happen in 40+ years. I'm not surprised, fuel pumps fail... I'm sure mine was replaced with what was available at the time. Any idea if the fuel pressure is any different between the two? Maybe I SHOULD be thinking about what we talked about in the PM... hmmm.

I believe the difference is probably the pump volume/flow rate and not pressure. I think the stroke on the pump varies slightly. Too much pressure causes needle seat leakage and creates problems.

[HawkX66]

Take a look at the applications for the 40727 (my pump). I've never noticed the note in the listing that shows specifically w/o the return line like Classic Industries listing( see below). I always saw the 70 L34 and never looked any deeper and figured mine was right. Ground Up is different and so are a bunch of others. My motor is a CJF which means its actually a 402 and would be considered a 1970 motor even though it's my born with 396 engine.

Classic Industries:
Applications:

•1969 396/375hp (L-78)
•1970 396/350hp (L34) w/o return line
•1970 396/375hp (L-78) after Feb 70, w/o return line

Ground Up's Listing:

Correct for 1967 Chevy 427, Chevrolet 396/350HP, 1968 Chevrolet 396/375HP, 1968 Chevrolet 427, 1969 Chevrolet 396, 1969 Chevrolet 427, 1970 Chevrolet 396 or 454 with Holley carb,

 I feel like I'm hijacking, so I'll leave it at that. Sorry for the bad info Dean...