In my experience, It Depends..

It depends on the design of the manifold and how much temperature
variation there is. The OSCO manifolds on my 350 Chevy have a small
section just where they bolt to the block that runs too hot for regular
paint, and I changed to high-temp paint and it's been OK.

Older engines I've had didn't get the manifolds that hot and regular
engine enamel seemed OK...

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Regards, Terry King ...In The Woods In Vermont

Capturing Live Music in Sound and Images
http://www.terryking.us