I'm new to El Camino's and well-versed in 1966 Ford Mustang's.

My son and I own a '68 El Camino Malibu. What type of body is it - a "A" body? And what generation is it - a 3rd generation?

Is this something I can find in the decoder section?

Your 68 is 3rd Gen and its a A body. You can get good info from the decoder. wellcome to the El Camino world :)