This is a lower compressor bracket for a 60's to 1970's Chevrolet small block with air conditioning.  The part number is 3995607 fits small blocks with under slung exhaust manifold and has some differences to another similar part with number 3511691.which fits underslung exhaust manifolds.  Mostly the 607 has full webbing between the two exhaust manifold mount points whereas the 691 has about 1/2" setback off the manifold for the webbing. AT PRESENT, I HAVE SEVERAL 691 ITEMS IN ANOTHER LISTING..