I have a MK IV 4 bolt 454 block and rotating assembly that could make in the range of 600 HP with proper cam and heads. Forged crank 7/16" GM rods, forged standard bore pistons and standard bore block. Comes with nice Fluidamper and SFI flexplate. Block is clean, but has one sleeve, and the crank will need a grind. A deal at $900!