My new small block Mopar (not an A body)
That thing is awesome! I remember many a winebago on the highway when I was just a kid,and pretty sure I saw one of these.
The 318_3 is a heavy duty truck version. I've seen several in 4X4's and the like. I dont think there is much difference from a regular 318.
I should make a small correction,as there are some sources that claim the -3 had moly rings,special valves etc. Im not sure if it is the heavy duty 318? That engine had an M in the vin #from 8-82 and an S from 83 to 88,and had a 4 bbl so probably not