THIS IS A USED EDELBROCK PERFORMER RPM SMALL BLOCK CHEVY ALUMINUM INTAKE MANIFOLD FOR A 1955-1986 ENGINE. THE CENTER HOLES HAVE BEEN SLOTTED AS SHOWN TO WORK ON THE LATER STYLE CYLINDER HEADS---NOTHING THAT WILL PREVENT IT'S USE. THANKS FOR LOOKING AND CHECK OUT OUR EBAY STORE FOR OTHER GREAT DEALS!!!!!!!!!!!