I wasn’t able to find a casting number on mine, it may be covered by a bracket or some other part.
I did see something lower down on the block, to the left of the distributor but it looked like a 3 and one other character I couldn’t read.
I looked in my old manuals, the only mention was in a Ford Service training guide that called out the block as -6010- .
To the best of my knowledge all these blocks are the same. The heads change depending on year and whether or not they are the base HSC or the HSO.
There is another member who I believe is on this forum, username is “rsiebeck” or something like that. He’s raced Tempos, and can no doubt tell you where to look, send him an email if you find his profile.