When did the 6.5 start using oil spray on the pistons. how is the oil spray delivered, does it come out of the rod and if so can thes rods be used to deliver oil spray to the 6.2 or earlier 6.5 that did not come with it stock.

It is part of the oil pick-up/pump system of the truck. I think the pump has a greater capacity and the oil nozzles are just below eack piston, spraying upward.

It is extra oil gallerys in the block, around '98-up, iirc - those blocks had a bad problem with cracking main journals.


To get a good block that won't crack, you'll need a 2002-up version, improved design with higher nickel content for strength.