'73 LS4 EGR Valve Date Code

[George H.]

The EGR valve on the intake manifold of my '73 LS4 4 speed (assembly date T0619CWM June 19, '73) is stamped with the GM logo, part number NR 7047066 and what I believe is the date code, 344 1 . Does that stand for 1973, 44th day (Feb 13), 1st shift?

[Joe L.]

Re: '73 LS4 EGR Valve Date Code

The EGR valve on the intake manifold of my '73 LS4 4 speed (assembly date T0619CWM June 19, '73) is stamped with the GM logo, part number NR 7047066 and what I believe is the date code, 344 1 . Does that stand for 1973, 44th day (Feb 13), 1st shift?

George-----

I've forgotten how the date codes work on these valves. However, the GM #7047066 is the correct valve for your application and, as far as Corvettes go, was uniquely applicable to your 1973 LS4 application.

[Tom R.]

Re: '73 LS4 EGR Valve Date Code

The EGR valve on the intake manifold of my '73 LS4 4 speed (assembly date T0619CWM June 19, '73) is stamped with the GM logo, part number NR 7047066 and what I believe is the date code, 344 1 . Does that stand for 1973, 44th day (Feb 13), 1st shift?

The EGR date code format changed from 1972 to 1973 (calendar year) from a two-digit year code to a single digit year-code that follows the julian code. So, you should expect three-digit for the day of the year and then a single digit for year. So, 29031 would be the 290th day of 1973 with "1" representing the shift.

Your 344 1 format seems to be missing the year digit. Look again and see if its faint. But the part number JL listed is consistent with the broadcast code you list (NR). This is the "expected" format. Whether your EGR date code deviates from this date code format...is conceivable.

[George H.]

Re: '73 LS4 EGR Valve Date Code

Thanks for the information. I'll take another hard look and see if I missed a number.