okI have two sets of Gen 4 LS Rod, and 1 set has this notch on both sides of the big end. The other does not have any notch. This notch is apparently factory as Google searches have shown other people with the same notch. I'm wondering if you know what the notch is for and whether it's worth using the notched or unnotched rods.
Both rods are 3984 castings numbers.
I'm guessing that maybe this is used to spray oil up on the cylinder wall but I've never experienced the need for that in the past and I don't know why that would be a need now. Both sets of rods are factory full floating pin rods that require the spring clip on the wrist pin, and both sets are out of 2nd cam bore size 6.0l NON-AFM 24x Reluctor engines with rear cam sensor. (so technically gen3 blocks with stock gen4 rods).. LQ4's which I think I forgot to mention. Sorry, can't see most of what I already typed as your forum doesn't play nice with my phone...
Anyways..
Thoughts?
All I can offer is theory. I would guess the same, it must be for oil spray in cylinder area. This would assist in cooling the piston down. Now I would guess it sits on the trailing side of crank rotation when the engine is assembled. That way it hits the piston on the way down rather than the way up. If my theory is true you should have four connecting rods with a notch one way while facing you and for the opposite. Personally, I would prefer the ones offering extra cooling. I'm willing to bet the ones with those notches came out of a vehicle with a towing package or something heavier duty. Side note, don't forget to get the rods checked for being out around. They tend to stretch.