1970 Skylark exhaust manifold

I removed left side exhaust manifold to repair exhaust leak on 1970 Skylark with hi-comp 350. (Fortunately no broken bolts.) Looked inside the manifold while cleaning it and noticed what appears to be remains of an internal support/boss in area of lower center through bolt. Was there something here to help equalize torque through this unsupported area? If so, can I repair this? Also, any source for replacement bolts, especially the long (approx 3.25") one that's half eroded away? Thanks.

 

Use the member search function to find "carmantx", he will have manifolds and spare bolts for you.

 

If you plan to keep the car, use stainless bolts and some anti-seize on the threads.

 

Thanks for your reply.