The end mounted fuel bowls on the Holleys will make it a little tough to accomplish. So an Offenhauser #5206 360 degree low profile manifold would require sideways mounting the carbs with Offy adapters #5832 with linkage kit #5967.
These adapters and linkage kits could possibly be used with a CH28B if the plenum dividers were milled out. There may be something available from Edelbrock, too. According to Hughes’, a CH28 is supposed to flow really well if port matched to the flange gaskets.
The other option is to mount the Holley’s in-line with Offenhauser 5701 180 degree high rise manifold with part number #5880 adapters that space each carb 1/2 inch from center.
Personally, if I we’re going to try the dual four setup, I’d go with the CH28. I’ve heard more bad than good about the performance of the Offy dual quad intakes. I honestly like the street dominator and a 800-900 cfm carburetor for this one.