Regarding replacement camshafts, OEM vs. aftermarket/replacement. When I was getting ready to upgrade the cam in one of my cars, along about 1980 or so, although when our heavy line guys in the shop changed out a camshaft, they just replaced it, as far as I could tell. No mention in the OEM's FSM about particular procedures and such. Although it seemed that our shop guys "knew what to do" in these cases. Seems like the old GM EOS can had a notation on it about the product being recommended for camshaft replacement lube. Still, no recommendation about the "30 minute" break-in and such.
Usually, once the engine was initially running at "fast idle" and the valve lifters were adjusted, then they'd shut it down and install the valve covers to keep the oil from splashing everywhere. Once that was done, the engine had already run for 15 minutes or so. With the rpm level varied to check for other operational issues. Then, the vehicle was taken out for a test drive. Which could last for at least 15 minutes or so, with varied engine speeds and such. Maybe some "heavy throttle" for good measure. So, the engine basically got the same amount of run time, just in segments rather than all at once.
Many of the heavy line guys, back then, knew how to build motors and were drag racers. So they probably already had knowledge of the cam break-in procedures, soaking the lifters in oil overnight, and making sure that everything was liberally-oiled upon assembly. Yet, the bulk of these things would be "invisible" to the customer. In that respect, that's probably why the FSM did not mention these things as the techs already knew them?
In the earlier 1980s, we hired in a light-line guy who had recently graduated high school. He wanted a better cam for his '66 GTO, so one of our guys callaed the local speed shop and got him what he needed. Apparently, he did not follow the break-in procedures as the car came back in a few days with a camshaft issue. A lobe or more were highly worn. Which was deemed "defective cam shaft". That's when it became known that a cam warranty is between the end-purchaser and the speed shop should not be involved. In this case, they got to be.
Another issue might be the disclaimers which some OEMs put into the FSMs and such. About those publications are designed to be used by "trained professionals" (or similar), which means they "know something" and "have experience" in what they seek to do.
On the private shop side of things, it seems that everybody knows about the cam break-in period situation. Prevalently-mentioned in many camshaft catalogs, too!
My initial suspicion was that the OEM level of Parkerizing/hardening process for the cam lobes was more robust that what the aftermarket did. That the aftermarket people knew the least amount they could get away with, just as the OEMs knew similar but also that the cam's had to last at least for the warranty period and longer, so their "stakes were higher", so to speak. The fact that some aftermarket cam sellers started having the option for a more robust hardening procedure for their cams tended to prove my point.
Typically, camshafts last much longer than 88K miles of continuous use. One that has been inactive for a good while might gain some surface rust on the lobes, which can easily be rubbed-off when the engine is reactivated, hopefully. In this case, the recommendation for the new cam and lifters was probably an "insurance" issue rather than a "worn out" issue?
As the engine now has several hundred miles on it, with no more of an issue than it now has, perhaps things will continue to be good.
Happy Holidays, Y'all,
CBODY67