3769716 and 3739716 have been listed by various sources as both being used in 1961 (1958-1963).
If you cannot find an engine serial number, and if those block codes were used in trucks and cars, you would have to check the lifters to see if it was a truck engine (mechanical lifters) or a car engine (hydraulic lifters).
The engine serial number should give more information about the model of the vehicle the engine come in.
