there were numbers behind the wiring harness b09k8m4 then there are numbers on the drivers side valve cover 53040-202ab so can i tell by this ? the guy lives 100 miles away and cant seem to find the 53 stamped on the side of the block

 

if it was a 53 block its not stamped into the block it is a boss casting about 1.5" tall numbers on the side of the block just above the oil pan rail