How about inserting a Y inline between the transom pipe and power steering cooler (first thing the intake water cools) and adding the pickup line there? Would I still need a pressure relief line?
My thought is that would still allow flow through outdrive, and potentially reverse flow as a pressure relief if pickup provides too much pressure.

not to promote one site over the other
But once you get the correct sierra part number from thier website
Amazon, west marine. Marine warehouse and a few more have them
Just have to find best deal
I did Amazon because of speed
But it came from the Sierra store there
Good luck

Turns out that Sierra doesn’t carry one, but there are lots of options in the $200 range. Be here tomorrow.

Got one!