Quadrajet bolts

[commodorenut]

Someone can correct me if wrong, but I think for the bolt it means 5/16" thread size, 18TPI, 3.75" long.

You're right, and they're commonly available at a *good* fastener place - I bought new ones when I rebuilt the Brock, as the old ones had corrosion on them, and half wrecked the threads in the manifold getting them out.
The heads on them are metric now, instead of AF - that's the only difference.