Ok fellow gear heads.

I'm about to install CMI Headers on my 454. When I noticed some rust starting in the #5 exhaust port of the cast log style manifold I was removing.

Not sure how to deal with this ? I guess I can do a compression check on that cylinder to make sure there isn't a weak spot in the head gasket or chaulk it up as reversion ?

Any clues or specifics on what it could actually be ?

Appreciate any facts.

Cheers !

Was it only in the manifold or also in the exhaust port in the head? If it was just in the manifold you should be fine. If it is in the head then I would do a leak down just to be sure. What HP are your motors? Do you know what the cam specs are?

Looks like it was primarily in the manifold port.

duration at .050 the Intake is 230 and exhaust 236
lobe 112.0

I'm installing CMI's E tops this week.

Had the cheap log cast manifolds on it.

I'm also wondering if the internal flappers in the tailpipes get stuck at times and create back pressure ? I was looking at the butterfly flappers yesterday and you have to give them a pretty good push. Also noticed a good amount of soot. So I may have to install a Fuel Pressure regulator for the Edelbrock too.

Starting to pick up all these clues the motor is leaving behind.

Thanks for being you !