The correct location should have been on the rear of the block just below the cylinder head and on the left side. ........
+1 - Drivers side head or block on 68- up FE's. IMHO more often on the block as they were instructed to do - but NJ and sometimes later at Dearborn (must have been one worker that didn't get the message

they can be found on the head rather than the block. There are examples from 68 NJ of them being placed on the intake - another odd ball worker

San Jose seemed to be the best at getting them on the block - followed by Dearborn but have a fair share from there on the head. More of the NJ ones I've seen or have pictures of were on the head.
Thanks for sharing with the site