there should be a name plate on the side of the block with the engine information on it.
usually where the bottom of the block bells out, not sure which side though.
As for the year? these were made before yale started using the suffix letter on the end of the serial number to identify the year, they only started doing this in 1995 so you'll have to give the serial number to the mfg so they can tell you when. This is a pre 1995 truck though.