Pettis Performance 598ci Big-Block - Big, Wild, & Nasty Part two Photo Gallery
A BHJ cutting tool was used to add an O-ring in the block and a receiver groove in the head. Pettis said he prefers to add the ring in the block because if the head ever needs to be repaired it is one less modification required. The deck rarely gets re-cut over time, which is why he prefers to have the O-ring in there. A 0.041-inch thick ring is used to help seal the heads to the block.