I just picked up some Fel-Pro intake manifold gaskets for my new 350 TBI, but after looking at them I'm confused. . . the rear ports on the gaskets are blocked off with the exception of a little hole? Why are the rear water ports blocked off?

 

if i remember right, if you look at the back of the intake, there aren't water passages in it back there unless you have a intake for a truck TBI.

 

No, there are passages in the back of the Edelbrock intake. I believe a heater hose sits over one of the back passages.

So does anybody know why the back passages are blocked off with the exception of one tine hole?

 

I really have no idea, but it could have something to do with balancing the flow out. I doub't it would hurt to open them up.

 

Yes the heater gets its hot water from the rear passage in alot of cars.

It's restricted so that in cars with that heater hookup, a limited amount of the water goes through the heater; i.e. the water is forced to go through the radiator, instead of all circulating through the heater and not getting cooled.

 

Yeah, I bought the same Fel-Pro gaskets for my Edelbrock Performer TBI and they had the same little hole. The stock gaskets are also blocked off in the rear, I took notice of that when I removed them. Anyway, these gaskets have been excellent and there is nothing wrong with them.