413 RB Industrial motors had different heads and intakes, but I've not seen any small block Mopar with different appearing heads or intake, Some of the big trucks with a small block did have a carb with a governor on them, but I would be surprised to see a motor home with a governor carb. The governor carbs were usually reserved for big trucks hauling heavy loads so the carbs didn't shock the drive +train and cause breakage. Of course the 340 TA or AAR came with the 3 2bbl carbs.
But we are talking about 70s Mopar, there is no such thing as never. If a customer checked the right boxes when ordering, Chrysler would put pretty much anything any where, if the customer was willing to pay.
Lets start with the basics, is the distributor in the front of the motor or at the rear? Gene