exhaust manifold bolts

[rddaves54]

I need exhaust manifold bolts for the head. I bought new manifolds and the old bolts are worn out and rusted away. I went to Chevy dealer they only carry metric. I went to Lowes but was wondering if their bolts would be strong enough? Can anyone tell me where I can get a set for my 350 72 engine? Saw one set on E-bay.

What size washer goes on the bolt to the harmonic balancer? I believe mine has the washer for the big block because it goes over the hole and not into the hole.