Right. I had mustang with em. The thing is that they are a 4" bore. I was thinking about a junkyard build. And the OM617 has a 3.57 bore. That is the same as a .020 over 4.6/5.4 modular motor. The stroke is almost identical to the 4.6. I couldn't exactly pin point the rod journal size for a OM617 but I think its 1.88 which a forged mod crank can be turned to. Offset grinding could take care of differences in deck height and control how far the pistonn is in the hole for compression reasons. As I was contemplating a JY build I figured the only motors in a junkyard with forged rods and pistons would be in a diesel. After looking at 7.3 IDI I saw the rods were to long at 7.1 or so. I also consider the 6.2 Chevy but info is scarce.

Since I have a local scrap yard with a couple 300SD I know I could get the rods and pistons for less than $100, maybe like $50 probably. But if the pistons are cast it really would be a waste of time in a boosted app.