1996 7.4 LX MPI.

I haven't had the current manifolds off yet but ordered a Merc. gasket to inspect the interior condition. I then ordered a full engine GLM riser and manifold set. I see the GLM's have 4 water jackets on both the riser and the connection to the manifold. The the supplied connection gasket (and the Merc. I ordered) has port matched holes for 2 of the jackets and pin holes for the remainder. Why is the water flow restricted so much? Is there a negative consequence for using the alternative 4 full jacket gasket?

Thanks
Ketih

Ayuh,.... It depends on the t-stat housin' used,....

If ya need the restricted gaskets, it'll over heat with the open slot gaskets,....

I have never gotten a good answer. which T stat housing with which gasket?

just another jist of it - restricted gaskets are used because --- to keep the manifold warmer to help against condensation forming then running down the internal walls of the exhaust system into the exhaust side of the heads.

Too cold of exhaust manifold and riser forms condensation especially after engine shut down and engine heat soak.