It is official, rods are toast. Now rebuilders

FWIW, my procedure:
1. At the initial startup, run the engine at 1500 rpm like always with a new cam for 15 minutes or so. No need IMO to go faster than that; the /6 cam oiling is mainly from the rockers down through the lifter gallery combined with perhaps some indirect splash oiling from the con rods. If the pump is at full pressure at 1500 rpm, no higher RPM's are going to increase it. Re-check valve clearances after the 15 minutes and again at 20-30 miles.
2. Driving the first few hundred miles, start out easy and then increase the piston/ring load with gradually increase throttle openings. Vary the RPM's all over the place. I did not put our rebuild to full bore throttle for about 250 miles.
3. Change oil and filter at maybe 300 miles and again at that interval. We keep out engines pretty clean on the inside so I've never seen the need to do an earlier oil change.
4. Take compression readings sometime in the first 100 miles; just to see that everything is pretty even across all cylinders.

There is nothing spectacular or unusual in the above. What we did find in our recent /6 rebuild was that the engine smoothness improved noticeably throughout the first 500 miles. I can't recall any other engine rebuild where the engine was not at full smoothness in just 50 miles or less. We used Hastings rings with the moly top so they should have seated in quickly; it may have to do with the rings seating or something else that I have not figured out.

It was unique in my experience. But new car owners 'back in the day' were told to use a gradual break-in process in new engines like described above; it was even described in a lot of owners manuals. New engines and metals and such seem to have done away with that requirement.

BTW, we used standard Castrol GTX off the shelf with no special ZDDP additives. The zinc contents of new oils is not all the much below the old oils anyway. And a /6 cam has such soft valve springs, it probably does not matter what you use. In fact, we had the rocker shaft flippped upside down and did not detect it until near the end of the 15 minute break-in!! No wonder the rockers weren't dribbling oil! But, that did not hurt this cam at all (a Dutra torque regrind with his reground lifters). The moly cam lube did its job.