intake manifold end seals

IMO silicone gets a bad rap because the surfaces were not completley free of oil before applying it.If there is even a trace of oil ,the silicone will not stick and it will slide and eventually leak.At that point you could add a gallon of silicone and it will never seal.The key is to have it clean to begin with.Lay a thick bead of it down ,allow a few minutes for it to start getting tacky ,then install and tighten down the intake quickly before it dries.Let it sit for a few hours to "kick" before exposing it to oil and your home free ...