On the 440 Sp2P we sat it down next to a 1968 383 2bb Iron boat anchor. the ports were about the same on both the carb and head ends. So yes a Marble may block it but its a big marble.
Understanding on a 440 a 383 2bbl port is NOT a race port but its not that bad if you KNOW you will not be drag racing your 32 foot long Winnabago. Will it pull past 4500 RPM, YES but it will be lazy.
The head side of a 383 2 bbl intake port is the same as a SP2P 440 ?
I haven’t seen that type boat anchor in a loooong time but I sure don’t remember that
