What is the reason that the rear coolant passages of the intake manifold gaskets are extreamly restricted? What whould it change to have unrestricted gaskets vs. restricted?

 

https://www.thirdgen.org/techbb2/sho...hreadid=118003
Maybe this helps?

 

nope, sorry tas but that don't help at all, they are just talkin about the hoses for the heater and stuff, my question is that on the intake manifold gasket in between the head and the intake manifold, why is the rear coolant passage of the gasket blocked off mostly and there is a hole the size of a pen or so in it, mind you not on all small blocks intake manifold gaskets but some like the ones specified for our engines, what is the difference between the two? Why would gm want to restrict coolant on some engines and not others?

 

well one of the reasons might be that our heater line is in the back of the engine insted of the front. Maybe if they didn't have it restricted a bit then cool coolant would only get thought half the block?