I know is sounds different... out of a Merc, It was a wagon...not sure if it was a 605. It just was worn out as it came from a junkyard car with lotttttsss of miles... anxious to get it rolling. The rebuild was around a hundred and it works great...
I just can't figure out why a company would sell stuff that is apparently not working well and seems to be a safety problem...and then not try and be helpful! Gearheads should be ashamed. As for me, I am amazed at your odyssey here.
Oh...you are not the first to be surprised by that box in a FoMoCo... I guess I was and then lots of others... no knowledge of why.