1973 ERG Valve Date Code

[Thomas R.]

My original EGR Valve NP 7047065 does not show a date code. Can anyone tell me is the date code inked or stamped in the housing. If inked what color and where and how is it displayed? Could you give an example of what it would read.

Thanks

[Jimmy P.]

Re: 1973 ERG Valve Date Code

Tom,
By the number you list and the broadcast code, you have an L82 Automatic. The date code is stamped on the valve. At least my 73 L48 is. Early 73's with EGR manufactured in calendar year 1972 have a one or two digit year designation. Ex; 290721 translates as the 290th day of 1972. (Julian Date). There may or may not be a last digit present. "1" in this example stands for the shift or assembly line. The code changes in calendar year 73 and 74 according to the JM to a single digit for the year. An example might be for a valve built on the same day in 1973 would be "29031". or "29041" for a 1974 valve. My 4speed L48 valve is numbered 7040318. My build date is 01632- 16th day of 73-second shift. I would include a photo of mine, but it is in the shop at this time having the original intake, and carb installed.
Hope this helps.

[Joe L.]

Re: 1973 ERG Valve Date Code

My original EGR Valve NP 7047065 does not show a date code. Can anyone tell me is the date code inked or stamped in the housing. If inked what color and where and how is it displayed? Could you give an example of what it would read.

Thanks

Thomas------


I've never seen one that didn't have the date code stamped (embossed) into the valve cover just like all the other information on the cover. Maybe some exist that were otherwise dated but I've never seen one. So, if yours is not so-stamped it's either a factory mistake or, perhaps, no coding was used for some period of time. 1973 was the first year that EGR valves were used on Corvettes and most other GM cars so it might be that there were some "irregularities" that occurred early in Rochester EGR valve manufacturing.

[Monte M.]

Re: 1973 ERG Valve Date Code

Here is a picture of a 73 EGR. Is this the information you are looking for?

73 LS4 3.jpg

I am not sure if 74 is the same. I have a Sept built 73 EGR valve in the garage. If a picture of it might help you at all, just let me know and I will post one for you.

Monte

[John S.]

Re: 1973 ERG Valve Date Code

Reply to an older post, here's another data point for '73 EGR Identification.



P/N 7040299 date code 308 21 (zoom in - 2 is extremely faint) Nov. 3rd, 1972 on an L82 4 speed car. Engine build date Dec. 6th, body build date Dec. 13th.