You didn't snap any bolts holding the manifold to the block. The manifold doesn't connect to the block, and it's not held on by bolts. It's held on by nuts on studs that thread into the head.
Well, what actually happened is you did a "readyyyy...
FIRE!!!...aimmmmm". You picked up wrenches and dove on in without first reading up and asking questions about what you were about to do. You would have been pointed at articles like
this and threads like
this, and you would have learned that It is very much worth your while to get the
good gaskets for the manifolds-to-head and intake-to-exhaust junctions.
