Any one interested in the oiling mods I did?

Duane said

You and I have had this discussion before. I have a 1969 340 block that does not have counter bores in the bearing saddles. Chrysler began adding those counterbores right at 12 o'clock. The counterbores overlap the oil feeds from the galley. I believe that corrects the timing and if you slot the bearings as well, it increases the dwell fill time to the rods as well.

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If that was the case, the a full groove bearing or even a 3/4 groove bearing would work. And it does. Up to the point the RPM, the oil viscosity and loads need the oil there at full flow and pressure.

I have no doubt that grooving the bearing can help. But, if the theory of just slotting the bearing or using a recess where the main feed and the cam feed comes together was a fix, you would just have the hole in the bearing at 12 o’clock and that would be the fix.

Then you can use 1/2 groove bearings and not have the hassle of a crossover or anything else. Any time you force the oil to make a course with more kinks, and tighter kinks, the less effective it is.