Modifications to Offenhauser 1 1/2 carb spacer Thermoquad to Holley pattern ?

Pardon my French but that will be a fuel distribution **** show. Putting the hose to that setup will make it a full fledged disaster. I see nothing good with any of that, and the nitrous will exacerbate everything by an order of magnitude. Just my opinion but at some point you should consider the intake manifold you picked is hardly vintage, and vintage is in the eye of the beholder.