an STR -12 has looong runners inside that are as long as most tunnel rams. Long runners means column velocity and steady ram pressure. To make this work you need a right carb to feed the left bank and a left carb to feed the right bank, just like the factory Max Wedge and Hemi crossrams.
This is why I have never been excited about the Offy inline 2x4 manifolds - VERY short runners.
Most of the old Mopar factory in line two 4 manifolds were dual planes with longer runners, as were the Edelbrock D-64/D-66 and their big block version which is still available.
As the quote below says, in my experience I have never had to spend a lot of time tinkering and tuning my dual quads. I have 2 500 Edelbrock AFBs on this motor):