1969 Intake Manifold Gasket Replacement - How To?

[Jim R.]

1969 350/300 - how to replace intake manifold gaskets?

I've read several threads here and there, but not sure I completely understand the procedure. Original manifold was replaced with an Edelbrock Performer. I have purchased the new gasket and can of Gaskacinch from Edelbrock. I also picked up a tube of Red RTV Silicone.

I think I have the "too many cooks ..." syndrome! I need an expert Chef with a recipe!

My question concerns the use of the gasket sealer and the silicone. As I understand it, the Gaskacinch is painted on the underside of the gaskets and its tackiness holds the gasket in place around the coolant openings.

The confusing part is the silicone. I've read that you should "smear" a small amount around each opening on the top side of the gasket and then put a 1/4 inch bead at the front and back. Does this mean just along the front and back of each gasket, or all along the front and back of the entire engine block - or are both incorrect?

Thanks, Jim

[Jim T.]

Re: 1969 Intake Manifold Gasket Replacement - How To?

The bead of silicone is used if you are not going to use the original type gaskets, rubber at the front and back of the intake/block. Using a dab of silicone references where the original type rubber gaskets meet the intake gaskets on the front and rear at the 4 locations.
Later model engines used the bead of silicone replacing the rubber gaskets at the front and rear of the intake.

[Joel F.]

Re: 1969 Intake Manifold Gasket Replacement - How To?

Jim,

Some people use the gasgacinch, others do not. It certainly won't hurt. If you are using basic replacement style gaskets, a lot of people put a thin (very thin) bead of rtv on the top of the gasket around the coolant passages. If you choose to use the rubber end gaskets, the tab that overlaps the intake gasket goes on top of the gasket.

[Terry M.]

Re: 1969 Intake Manifold Gasket Replacement - How To?

On originally installed intake gaskets -- with the rubber end pieces, I see a small dab of black RTV (Room Temperature Vulcanizing) sealant at the corner of the intake -- where the front and rear wall of the cylinder case meets the head. RTV is often referred to as silicone sealant.