Here is the merc:
typical tunnel ram but with custom top.
No one aftermarket offered true tunnel ram for vortec heads.

SB ...yeah i know the chevy one is different....but the mercruiser one i think i somewhat based off that desing....i think he may have the Mercruiser 320 EFI "high performance" intakes...they are a tunnel ram two piece style...based off what i saw in his pictures...

i think weiand had something close:https://www.summitracing.com/parts/wnd-7542p/overview/

Sounds like time for carbs or Holley efi

Nope. But getting closer.

Too bad John Lingenfelter wasn't still around (for many other reasons too of course) as I believe he was the one who designed this intake for the earlier scorpion engines. Change on these newer ones is just the bolt holes for the Vortec heads. So, who cast it ? Edelbrock ? Holley ? Someone else ? I guess it doesn't matter because it's not like they would cast a few. Bummer !

To me, they look like the old Victor Pro-Ram (Edelbrock) but with rounder runners.

I ended up finding someone that could weld it is a very hard place to get too. I couldn't find another one to purchase. All the external engine parts are now going to Vincent Custom Paint next week. Going to get rid of the old decal on top of the EFIs and come up with something really cool painted.