[Double Venom]

Well it certainly looks like "Carol Smith" has been updated on the attaching hardware.
It does seem to be the consensus that grade 8 is the best choice. But, in agreement to some people here also 'in the know' AN is the ultimate bolt assembly for seat belts.

Now, not to start another debate but position of the shoulder straps also has some major grey areas.

NSRA / NHRA: Level to the shoulders to a maximum of 4"s below the shoulders. (This can be very tough in street rods!)

Simpson: Should have a downward angle?

All kinds of variations come into play here, I think a good dose of common sense falls into play here.

And, thanks to everybody- I learned a lot, including the right way!
DV