I am completely confident in the lifter bore extension gallery creation to the #3 cam saddle area.
With the oil plug removed, I can insert the drill all the way in and it will not take any more material off the lifter oiling holes. At least it shouldn’t.
I made some measurements, and the bit will drill a hole 20mm from the lower opening of the exterior lifter bore.
When I look at the case from the top, if the oil gallery is drilled into the closed #3 cam saddle towards the flywheel side, I think there will be enough material to not drill outside of the case.
I’m going to measure it all again tomorrow and try to make some internal case markings as well that will help me.
It really is a close one.
I can see why attention is given to how the execution of this mod is so important to avoid failure.
What’s really sad is that the case itself, if the mold was slightly modded, could have additional material added to the area. It wouldn’t add much weight, and would basically just thicken up the exterior wall of the one inset area.
There’s this entire indent that could be filled a bit more during casting and that would make this mod so much easier to do.
Hell, The case creation could be slightly redesigned to allow for this mod as a permanent addition. At least it would feed more oil to the 1/2 side.