What's going on with my manifold heat shield?

[1971c10longbed]

The heat shield on my 71 c10- 350 was rusted, pitted and UGLY.

Painted it with extreme heat paint.... it burned right off.

Had it powder coated.. and this is what's happening now...

I don't hear any exhaust leakage from the pipe or manifold.

Anyone have any idea or suggestions of what's going on or how to keep it looking good?

Thanks in advance..

[Bigdav160]

Is that heat getting to the valve cover too? I say you have a leak

[1971c10longbed]

there is discoloration on the valve cover ... you thinking a cracked manifold ?

If I have to take it out... what can be done to the manifold to prevent it from looking like it does now?

[HO455]

Eastwood manifold paint.

https://www.eastwood.com/paints/hi-t...st-paints.html

[1971c10longbed]

thanks ... time to tear it apart.. again

[Ironangel]

Take a close look at the manifold, I think you'll find heat cracks caused by a retarded timing situation... https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAQ Also, that white haze is probably zinc out of the smoke from the paint being burnt off the heat shield...Heat shields were never meant to be shiny bling. I suppose you could have them ceramic coated professionally by these guys, Jet-Hot High Performance Coat, or blast them clean and spray on some VHT Flame Proof and bake them in the oven when wifey is at work... You didn't get that info from me! lol

[1971c10longbed]

thanks .. i will check the timing

[toolboxchev]

They had a problem for years with the manifolds cracking. I had a 72 with a 350 and it had some type of air diverters in the location you have pictured.

Most people ripped them off there due to accessibility problems when changing the spark plugs. I know that is what I did on that particular truck. When I got my 70 it did not have them on there.

Maybe someone can post a pic of those things for reference. Seems like your going for an original look.

[1971c10longbed]

thanks