Right Gasket Sealer for Intake Manifold

[capriceforever]

I'm replacing the tin splashpan intake manifold gasket on my 1990 caprice with the Olds 307 engine. I've got some conflicting information hopefully someone can clear up for me.

My shop manual says to use Silicone RTV on the front and back of the block, and a aviation grade sealer around the ports. (capable of resisiting fuel vapors)

The Felpro gasket kit however comes with Silicone RTV, and says to apply that on the corners of the block only, (comes with composite strips for front and back of block), and the kit says to apply Silicone RTV around the water ports only on the intake gasket. But nothing around the exhaust ports.

So should I apply silicone RTV around the water ports, and then aviation grade permatex around the exhaust ports, or can I do like my shop manual says and just use aviation grade permatex around all ports, water and exhaust?

Really want to get it right the first time!

Thanks

[Nym]

I have always used a silicone based RTV sealant on intake gaskets and nothing on the exhaust side. Come to think of it, I can't think of ANYBODY who has used sealant on exhaust ports..........

Good luck

PS: I don't even like using those friggin rubber end gaskets. I've always laid down a nice bead of RTV in their place. no troubles to date (touch wood). My two cents worth....

[silicon212]

Use just the "valley pan" gasket for the intake itself. On the end seals, you can use RTV. Personally, I use a sealer called "The Right Stuff" by Permatex. This stuff I've yet to see leak, and you don't have to wait for it to set up - as soon as you bolt it together it can be used.

Don't RTV the intake mating surfaces on the heads or manifold - gasoline will over time attack the RTV and cause problems. Use Permatex #1.

[1986Z28]

i use rtv only on the end gaskets

[easterwabbit]

yes black RTV across top front and rear of the block, and sometimes i will also go around with a thin coat of it around the water port and each end of the intake gaskets, but not on all engines, it just depends on the condition of the gasket surfaces of the heads and intake, if they are corroded pitted then i will, if they are clean and smooth then i wont


good luck