Mark IV 454 block with mount point for mechanical fuel pump and two piece rear seal. Four bolt mains Same block as LS5 Casting #361959, Deck stamp T05165X Bare block with bearing caps, painted white Original bore - 4.251" Low hours in a boat $200 extra for a pair of oval port heads for rebuild We also have a forged 454 crankshaft with some minor damage to the rod journals We have six other 454s to sell. Ask for details. [Engine T]