Why are the rear coolant ports on TPI engines blocked? Is it better to use regular gaskets with open water passages? Seems to me that it would be better to be open.

Jason

 

Thats the way pretty much all SBCs came from the factory. Open gaskets won't do you any good if there isn't a coolant passage in the manifold. I haven't looked at a TPI manifold to see if it has them, i know most 87-later TBI/carb intakes actually did have a rear coolant crossover.

I don't know that having a rear crossover really helps anything with regards to cooling. Like i said, most SBCs that rolled off the line came w/ them blocked, and likewise, most aftermarket manifolds also have them blocked.