Found out after some troubleshooting today that my intake manifold has some vaccum leaks...The motor has new cast iron vortec heads and an edelbrock performer manifold. The motor has only about 40 hours on it. Can I run a bead of hi-temp silicone down the crease between the head and the intake? I really don't want to remove the intake if I don't have too. I've heard that the vortec manifold are prone to leaking since they only have 4 bolts on each side holding it down...2 in the front and two in the back.... Any thoughts?????

BH

I would take the whole thing off and re seal it. I have been having some problems getting mine seled right. if you have leaks on the side you may also have leaks between intake ports or worse, the cooling ports.

Better safe than sorry. just my .02

Attempting to seal from the outside is asking for trouble. You have to pull the manifold. Maybe you need a set of thicker gaskets to get a better seal. Have the heads been flat or angle milled?

Please, please, please listen to checkmate454mag. DO NOT try to reseal the intake like you said. You will have to tear it down, clean everything real good and reinstall it. Also DO NOT forget to check the intake and heads for flattness.