Thanks Tom, spoke with a fellow close to you in Monrovia, Paul at Paul's Carb shop. He was referred to me by the Offenhauser tech rep. A Pontiac guy too as he has a 66 GTO fully restored in his shop now. He said he had a 5499 Offenhauser dq manifold like mine in front of him and 2 small bolt pattern Stromberg 4A's that would bolt to it without an adaptor bolt-hole wise BUT ...

the throttle shaft actuating arms hit top of manifold runners on the lower front carb. I had seen this, even with the adaptors I have for my 4360's that raise carb about .750" the front throttle arm hits .. was just figuring I needed thick gaskets. Just discovered the gaskets in my Offy kits don't appear to be right ... they look relatively simple to make, will just cut my own, was going to trim adaptors as well as they have excess material overhanging carb flange. Trials and tribulations

Guess this manifold never worked without an adaptor with any carb, front carb anyways ??