nice pair of bb hp manifolds for sale.

I don't think my eyes are off. The B/E left side manifold has an outlet that points mostly down and back - the headpipe points right up at it. The C body has one that points almost straight to the driver's side because of the torsion bar - the pipe has to make a sharp bend to meet up with it. That left hand looks like a C. The right side is interchangable with all bodies, I thin kwith A also. It's the B/E left that gets used on the A body installs - and someone also sells a hybrid with a pipe and flange welded on them so they fit even better.

What is the casting number off that left hand one?

It's a 992 casting B body HP exhaust manifold.