What you said is what feedback I get, except for one and he is the only creditialed one to say so. I am not a machinist, I have only one cell that is of any importance to me, and it is curious that this issue is such.
I figured a histrength bolt would thread through the block and thread thru the bracket. It could be a thread on the bracket.
It is a rivet because there is no slot or crosstop on the head of the bolt. Visegrip screwdriver? And then deal with the alignment with the heliccal gear on the cam! I lean towards dead block, because of the alignment complications. Nowhere in the catalogs can you find the brakcet and tru pins.
Actually I do not no the answer...the truth.