72 Intake has rear water passages blocked

[brown7373]

I am installing a crate 350 to replace my original 350 that crapped out. The original intake has the heat crossover blocked, which I understand is fine, especially with me living in Florida.

But the rear water passages in the intake are also blocked, filled with some kind of solid filler.

I have owned this truck since 2003, driven nearly 80K with zero problems. It never overheats, even with A/C on in traffic in the middle of summer.

Is there some reason the rears are blocked? If it ain't broke, don't fix it, but why was that done?