And, unless you are being super Catholic about it, a lot of 4 BBls got tossed for late model tripower intake because.... tripower.
It was no trick at all to have your '66 intake end flanges opened up to take the 'big' Rochester 2GCs.
Lots of possibilities, but it sure would be great to have the 'hands-down' Pontiac 400 for all these applications. A FB guy is getting a lot carried away with a 1/12 '72 LeMans project, and is modeling every single square inch of the car, including the engine. Hopefully, he gets it finished and hits the "print at 50%" button.