UPDATE Rebuild first startup questions

scott wrote: Since your cam is not stock, is not the one used with the previous engine setup, it is understandable that the initial timing that works best may be different than before.

This is what I've been reading. Seems to be where the motor is happiest.

By ear and backed a few degrees from audible detonation is the best a lot of us can do. I'd be all ears for a more technical approach, too.

1. The "trace detonation curve". This is the timing at every available RPM that caused faint detonation.
2. The "mean best torque" curve. This is the timing at every RPM that produced the most power.
3. The "2% loss retarded" curve. This is the timing at every RPM that is retarded slightly from the "mean best torque" setting to create a 2% loss in power.

I would LOVE to see that document!

My paraphrasing of the break-in process was off a bit. 
Perfect Circle actually states to do the acceleration thing 10 times, stating no further break-in is needed but to avoid sustained high-speed driving for the first 100 miles.
Run from 30 to 50-55 full throttle (without lugging, and if an automatic, prevent kick-down or downshift) ten times in succession.
The idea is that the more extreme combustion pressures of that sort of load force the rings against the cylinder walls and wear off the high spots, breaking things in. 
People have very very very old-skool ideas on break-in sometimes such as it takes wearing off the machine marks, or that it takes thousands of miles, etc. That's not the case.
The ring machine marks should still show after many thousands of miles and sometimes the cylinder hone marks will show up to almost 100,000 miles in a well-maintained engine. 
Further wear is more extreme. 

So after cam break-in (which is mentioned only in some places....... some don't even mention it as necessary) do the ring thing and you are done. 

The timing in the SAE papers aligns with what was said about the ideal angle for peak combustion pressure - it's science and engineering. Those papers don't touch the full depth - I agree those interested in the WHY they do what they do - or SHOULD do  what should be done - would enjoy reading what the engineers had to go through to make our beloved engines as strong and reliable as they are. 

I still go back to my college books now and then, there's so much in them and it's hard to retain it all if one doesn't use it constantly. I have two shelves dedicated to the college books, and all the notes I took over those years.
I have the materials I got from the Ford and GM continuing education classes I took later as well as the Sun information on carburetion, etc.

Dana Corp said the break-in was the same for all ring materials, cast or otherwise. 
So many shops simply hone and don't know why or follow the proper procedures for cleaning, and cross-hatch angle, etc. 
I pulled apart a Ford out of a pickup that had an in-box camper on it, the engine was just shy of 100,000 miles and it still had hone marks easy to see. I have pulled apart engines with 30,000 on them and found no marks at all save for above ring travel or down low in the cylinder. There are many reasons - oiling, type of driving, heat, and more. 
AMC did what should have been done - the correct cross-hatch angle, their finish was fine and not too course. Check with the ENGINEERS and those who MAKE the rings.......... 

You won't gain power each time you flex the rings.......... you may be blowing carbon out or removing some deposits, whatever, but it's not physically or mechanically doing anything beyond that initial break-in prescribed by Dana, Hastings and others. Their labs have done more tests than the experience of all forum members combined, and they make the products we use and have to stand behind them. If they were wrong, they'd be out of business. 
You also aren't doing anything with the high revs that early in engine life because there's no wear vs. unworn to catch. In fact if there's anything there at all in the first thousand miles, you have issues. It may be a "feel good" thing, but it isn't helping or saving anything because there's no ridge or high anything to catch. That happens much later.
You could go a thousand miles, pull it apart, and not have a thing for a ring to catch on. There simply isn't that sort of wear NORMALLY. If there is, there's trouble. 

Be careful what you hear or read on honing and rings, too. I take my advice from those who MAKE the rings and test them scientifically over many thousands of hours...... not "this has been my success".
the pattern is more important than the "roughness" regardless of the ring. 
If the pattern is too steep you lose oil and have excessive wear - likely in your case. 
If it's too flat the rings will hydroplane, not break in well and you'll have oil consumption.
That's the science and facts of the matter from the makers and those who TRAIN top technicians. 

Here is a quote from Hastings (if ya heard of them, they make piston rings)
>Substantial controversy exists on the correct cylinder roughness for proper seating of piston rings, whether chrome, moly, or plain cast iron. It has been our experience that the use of 220-280 grit stones and achieving proper cross hatch angle produces a finish compatible to all three types of the above rings.<

And here is what "enginebuildermag" says - very similar, in the end these outfits often end up saying you can hone the same for all rings if you follow modern methods, correct angle, reversing the hone in the final steps, plateau finish, etc.
And gee, they are also saying "after a couple of hours things are broken in."
>According to one piston ring manufacturer, once the rings have seated, wear virtually ceases because the rings are now supported by that thin oil film and no longer make physical contact with the cylinder wall.

A plateaued bore surface will stabilize after about two hours of running. In other words, the rings will seat very quickly and experience almost no further wear. A more conventional surface finish, by comparison, may take anywhere from three to 12 hours to seat in depending on the grade of stones used. A bore finish honed with #280 grit stones will seat faster than one finished with #220 stones.<