Yes (the thermactor air pump bracket was originally -ed) painted on the block up through 69 - this includes 67. Sure I've got maybe a half dozen of those unless I've thrown some away recently
Have seen service replacements that were painted black
Splitting off from a different post discussing the color of the thermactor air pump bracket. The answer was that the bracket was painted on the block.
As a natural extension of the "right" answer, it is more than likely then that the bracket was mounted to the engine (and painted) at the engine assembly plant. Since in the case of the 289-2V in 1967 (and probably all engines) the thermactor model received a unique distributor (curve) and carb (tuning), it adds up that the bracket would also be installed there.
Furthermore, it would make sense that the thermactor equipped engine would receive a different engine number to distinquish it from the non-thermactor equivalent. While SJ installed a lot of thermactor engines, it was certainly not an exclusive deal. I've seen at least two reports of Dearborn assembled cars with thermactor. Engine numbers would be the mechanism to get the right quantities of engines to the locations where they were needed.
Looking at the Mannel book in appendix A, the "engine number" is a three digit integer. Continuing with the C-code as the example, there are 19 engine numbers spanning from 1964 to 1969. The variations account for the year, the vehicle (Mustang, Falcon, etc.), the transmission (auto/man), and specialty applications (taxi/police). There is no mention of thermactor at all pre-68. So apparently the "engine code" does not account for the thermactor system with the exception of 1968/69 302 engines as noted in the tables.
I've looked through the book and don't find the answer for thermactor equipped engines.
Looking at the engine number on my car, which was thermactor equipped, it is "289 E 67 FoMoCo" on the first line and "M
E-236-B 15" on the second line. The full "engine number" (Mannel's term) is E-236-B. Mannel's book refers to the "E" as the prefix, and the "B" as the suffix. However, it does not really provide any answers as to their meaning.
At this point, since we know that the thermactor 236 engine was equipped differently than a non thermactor 236 engine, I would propose that either the "E" prefix or "B" suffix provides that detail. Now if "E" as the prefix stands for "Emissions" that would make perhaps too much sense.
For those that are willing to share some "original" data from small blocks, please provide the engine (1) build date, (2) number (including prefix and suffix if any), (3) revision level, and (4) whether or not the vehicle had thermactor emissions. Note that the build date, number, and revision are engine tag line two from left to right.
Thanks.