This listing is for a set of (8) Hyper eutectic Pistons w/ moly Rings( Perfect Circle/Hastings) Kit. Compatible with Small Block Chevy 400 & Rod Length: 5.7". Flat Top, Four Valve Reliefs, Hyper eutectic Aluminum, Press-Fit or Floating, 5/64" x 5/64" x 3/16" Ring package. In Your choice of STD. .030" .040" or .060" over sizes.