HELP!  Does anyone know #'s on Y-Block, casting # ECZ 6015-C on side of block.  The 4 front main bearing caps have casting #ECZ 6329-A, rear main has casting # ECZ 6325-A.  This block was bored .030ths, decked .010ths and supposedly lined bored.  Why the difference in the main bearing cap #'s?  Thank you, Charlie, Central Fl.