Would this be a July 10 1972 SPD?

[GrandpaKevin]

Friend's 'Cuda restoration.

How late did they build them?

[anlauto]

I would agree with that

[Skdmark]

Yes, a SPD of July 10. That would be nearing the end of the production run.
The next model year's production would begin in August. There was usually a couple weeks gap in between.

[JS29]

Late July was shut down, Assembly line workers got there vacation, and retooling and maintenance was done for preparation for the next modal year.   

[6bblgt]

Hamtramck assembly for the 1972 model year was SCHEDULED at least until 7/28/72 & VIN sequence 2B532208