intake/exhaust manifold fasteners

[Ameer Antar]

So I'm planning on getting the head off now, and so, as I thought, I can't get a few
of these bolts off. I didn't think any of the intake bolts would be any trouble, but
the last one's allen head is completely chewed up. I'm thinking of using a screw
extractor to get it out. I was surprised at how soft the metal is in these bolts. I'm
planning on replacing all of them, including many others on the head, block, and
exhaust. I found the intake bolts to be M8 x 65mm. McMaster-Carr has some
stainless ones for $6.50/10 bolts. Can anyone recommend any other source for
these and the other bolts I'll have to get for this motor, or are these guys the
best? Anyone know what size the exhaust studs are? I'm thinking of replacing
these w/ stainless as well for longevity. Anyone have any arguments against
replacing all the hardware w/ stainless? Thanks a lot, and wish me luck for getting
these gosh dern bolts off; i need it.

-ameer