[collins10672]

the vin does not tell what engine came in these trucks.as stated above the best way to know if the engine is the correct year is to run the numbers on it.although you might have a 66 engine in a 66 truck it still might not be the original engine for that truck.there is really no way to tell if it came in a particular truck or not even if you have the build sheet the engine could have come out of a parts truck that is the same year.the 1966 trucks were the only year with option label attached to inside of glove box and these can be reproduced to state that a truck had options that it did not originally have.i would say that if you have a 66 engine in a 1966 truck that would be as close to original that you could get in these trucks.good luck.