I'm setting up a dual TQ set up for a 426 wedge, the Edelbrock 4 hole adapter looks to be the least restrictive and best matching. As you can see here, the adapter positioning will cause uneven flow and turbulence as it hits the metal between the 4 holes using the Mr Gasket adapters .the Edelbrock 4 hole adapter will be a closer match to the existing 4 holes on the intake.