Product details:

LS Series Engine to 1955-86 Small Block Chevy Perimeter Bolt Valve Covers Used to adapt 55-86 SBC perimeter bolt valve covers to LS series engine heads - Includes: 2 adapters, and hardware - Compatible with 1999 and up LS series engines - Made in Wichita, Kansas from aerospace grade, USA produced, billet aluminum - Uses factory style valve cover seals (551310)Will require sbc gaskets or RTV sealer on valve cover side Adpters are 1/2 inch thick