Good morning! Does anybody know what size bolts were used to attach the exhaust manifolds on 1966 B-body engines? Specifically I'm asking about a 66 Dynamic 88.

Also, doesn't anybody have an opinion about using gaskets with exhaust manifolds? I have a couple of Thornton manifolds that I was planning to install soon.

Thanks in advance for your wise and thoughtful guidance.

 

The bolts are 3/8- 16 gaskets no unless you have leaks and don't want to have heads or manifolds surfaced. Use never seize on bolt threads...

 

Thanks a bunch, Oldsmaniac. Always appreciate your experience and knowledge. --Craig