This listing is for a set of eight (8) 4.030" bore Sealed Power FLAT top pistons and a MOLY piston ring set (Perfect Circle/MAHLE or Hastings) compatible replacements for Mercruiser 350 cid 5.7L applications using the Chevrolet V-8 engine. P/N (8) H345DCP030 + 40564CP030. Piston specifications are as follows: BORE: 4.030" (+.030") HEAD TYPE: flat hypereutectic RING LANDS: 5/64"-5/64"-3/16" COMP. DISTANCE: 1.540" PIN DIAMETER: .9275". These are for all Non-Vortec engines with a 4.030" Bore.