Chevy Master Cylinder Julian dates how to read?

[RALLY]

Guys 72 Chevy Nova is own. Master cyl cast numbers read 5470409 D53 351
Numbers stamped on flat part of casting where the first brake line exits and these read
3 2 0 4 CL.

Can you help me out here and tell me what these numbers stamped mean?
Casting number i believe is 5470409 D53 351- these are julian numbers 351 days of the year
reading Dec 17th? Am i correct?

Now i dont have any idea what these numbers stamped are 3 2 0 4 CL? Any input is greatly appreciated.

[RALLY]

Guessing its a 1973 date coded Master Cylinder NOS rebuilt core. No bleeder screws in front or by the first brake line coming out. Any input?

[Lynn]

I am not good on these after 1969.

Maybe if you post some pics of the numbers, someone on here will know.

[X66 714]

Friday, Dec 17th 1971 is what I would've come up with also...Joe

[RALLY]

Joe, i agree with your answer. Do you think this Master Cylinder could be original to my 72 Nova SS that was built late January 1972? How close to you have to be to the build date to make it correct? I am hoping it could be original. Any thoughts?

[X66 714]

Joe, i agree with your answer. Do you think this Master Cylinder could be original to my 72 Nova SS that was built late January 1972? How close to you have to be to the build date to make it correct? I am hoping it could be original. Any thoughts?

I would probably come to that same conclusion but I don't know the correct cast number for your car. Have you talked to Mike Gibbons?....Joe

[RALLY]

No i have not talked to Mike Gibbons. Is he a member on our site? Love to talk to him about this. Any info on him Joe is appreciated.

[X66 714]

No i have not talked to Mike Gibbons. Is he a member on our site? Love to talk to him about this. Any info on him Joe is appreciated.

PM sent...Joe

[Jonesy]

I think the date code is the one stamped on the flat surface. Year and day of the year. 1973
204th day - July 23

[RALLY]

Thanks that makes sense for sure.

[RALLY]

After talking to a very good source with the questions i have, i am convinced i have a rebuilt Master Cylinder core that was installed by the original owner. Original MC is long gone.

[Starship]

As stated prior. 204th day of 1973. Definitely not your original.

[RALLY]

As stated prior. 204th day of 1973. Definitely not your original.

I have to agree. I had someone looking into this a very good source but never heard back. But you are the second person to say a 1973 stamped date code and again fully agree what you are saying. Its a rebuilt MC that has no bleeders. But the Master Cylinder part number had a 351 Cast date on it. Which can make it a late 71 cast date? Which probably would match my Nova. Just a guess. Thanks for your input.