60s /6 to 727 adapter

I have an 85 D150
Original/6, 727 equipped.
No adapter. Original trans still in the truck.
I replaced the engine, original one went to Michigan, is now in a 68 valiant... One of the regulars on the /6 forum had a /6 727 for sale a while back. . think it was Rick covalt.
They definitely made them for a while but not that common.....
But they never had an automatic OD trans while they also had the /6... For someone wanting to put an OD auto behind the/6 this adapter setup is needed.
I have heard rumblings of someone who made a run of aluminum aftermarket copies of the original cast iron adapter.... But never seen one.

I've got a question that comes up with stick bellhousings now and then. Would this need to be "indicated" to the block with offset dowel pins, etc?