My question: Did Chevy ever install "last year's engine" in a new truck
Yes, that is possible.
Your stamped 216 engine serial AKCA is correct for a 3600.
"NEW" models were introduced as letter I (Sept) every year....
So.... block casting date letters I, J, K, L (Sept thur Dec) would be used as the next year.
Lets see if this holds true.
What is your block casting date info.
Something like K 3 52.
