Metal or composite header gasket?

[Stump Jumper]

I am in the process of intalling the headers on my 6.8 (V10) Ford. Prior to working on the motor, I bought header (paper/asbestos/composite?) gaskets from Autozone. When I removed the stock manifolds, I found metal gaskets. Should I reuse the metal gaskets with the headers or go with the gaskets that I bought from Autozone, or something altogether different? Thanks in advance.

[Nick-B]

Good luck getting a consensus.

I don't know about the V-10 but on the 460 Ford, some folks (including myself) have had the best luck without gaskets. Just a thin bead of Hi-Temp RTV around each port and let it setup for a day. Found that trick on 460Ford.com.

If it were me, I'd do the RTV.

[Mike Canter]

Do not use composite header gaskets they blow out real fast. Copper or metal gaskets work great but I will back up what Nick stated. The only difference between what Nick does and I do is I put the high temp red silicone on the headers then let them sit for about 20 minutes so the silicone cures a little and skins over. Then I bolt the header in place and just barely just snug it down then let it sit for 24 hours before I torque the bolts down.

[Stump Jumper]

So, you guys have found that the silicone works better than composite? Silicone only, with nothing else?

[stepside454]

The silicone only works , but it needs to be very clean surfaces & a good quality header with thick flanges.
I had sanderson headers on my 454 in my hot rod for 6 years, never had a leak, no gaskets, silicone only.

[Mike Canter]

Stump Jumper we are talking the High Temp red or gold silicone. And that is correct, nothing else especially NOT a composite gasket. If you have to have a gasket because the sealing surface is messed up then use a copper gasket and the high temp silicone.