360 magnum block art

I recently picked up a couple of 360 magnum engines. One came with some interesting art work. Anyone seen this before?It is hidden under the CPS when in the vehicle so it seems kind of stealth,maybe the workers in the assembly plant are bored? What years did the blocks begin production in Mexico?

Gang sign? What set you claim, homie?

all 360's after 1980, IIRC were built in mexico. 318's in detroit (where the 4.7's are built now)