Thread: SBC 350 Intake Gaskets Not Sealing

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Assuming that this block has never been decked, clean everything real god and start with a fresh set of Fel-Pro 1205 gaskets – not 1206. The 1205 has a bit more gasket and will better seal with this head/manifold combination. Place them with the blue facing the manifold. I have used a very light coat of Gasgacinch on the heads of SBC engines for years – it’s optional, but it helps hold everything in place.

Put a nice bead of black silicone on the China walls and let it skin over. Use an extra blob at the corners.

Set the intake down gently on the engine and follow the exact sequence of tightening as recommended by Edelbrock. DO NOT over torque or you will squish the silicone out and have the same problems all over again.

If the block has been decked - may be a different issue.

Glenn

Originally Posted by glennsexton

Assuming that this block has never been decked, clean everything real god and start with a fresh set of Fel-Pro 1205 gaskets – not 1206. The 1205 has a bit more gasket and will better seal with this head/manifold combination. Place them with the blue facing the manifold. I have used a very light coat of Gasgacinch on the heads of SBC engines for years – it’s optional, but it helps hold everything in place.

Put a nice bead of black silicone on the China walls and let it skin over. Use an extra blob at the corners.

Set the intake down gently on the engine and follow the exact sequence of tightening as recommended by Edelbrock. DO NOT over torque or you will squish the silicone out and have the same problems all over again.

If the block has been decked - may be a different issue.

Glenn

Thanks for the informative post. Unfortunately I read this one too late,...! I have done everything as you have indicated, although I used 1206 instead of 1205. Hopefully the 1206's do the trick for me, if not at least I know what to do.

I also did more reading, and noticed that the rocker studs for the intake valves are not installed into blind holes on the AFR heads,...they go straight through into the intake port. I did not use any thread sealant on these, and believe oil was being sucked in through the bolts here; I made sure to remove all of them and apply thread sealant.

At the moment everything is drying, I will fire it up tonight and see what happens.

Thanks again for the information.