Heat Exchanger Gaskets - Which Side Up?

[vesnyder]

Installing new SSI's and replacing the gaskets. Got the gaskets and one side is different from the other. One side has a raised portion around the exhaust hole. Should the raised section face the block or the heat exchanger?

Thanks in advance.

[Bob Kontak]

I have never had a problem and I am sure I have installed them both ways with the many times I have had my exhaust on and off.

[cgarr]

I put the raised side towards the steel header and the smooth side to the alum exhaust port.

[jrolstin]

I did the same as cgarr. In Wayne's book it shows a slightly different style, but the folded side is up so that is how I installed mine.

Cheers

[vesnyder]

Looking at the gaskets that are on the car now it appears that the raised section is toward the HX'er, but not real easy to tell given these gaskets have been on the car for almost 30 years!

[jrolstin]

You're over thinking it, flip a coin and start driving. They will seal either way.

[Bob Kontak]

I always thought they were "crush gaskets" at the center metal ring. I took a micrometer to some used ones and they were the same thickness as new ones.