The factory specs for the pushrod lengths were quoted by "lsrken" in another post a few days earlier:
"Factory spec for Commando pushrods is 8.166/8.130” inlet and 7.321/7.285” exhaust.
For Atlas and P11 intake is 8.194" and exhaust is 7.351".
What LSRKen actually posted was the factory specs for pushrods post engine #12871 and pre- #123871, so him saying that the Commando and Atlas/P11 having different lengths was as bad a bit of information as Bogus saying that 650cc and Commando pushrods were different lenghts.
Anyone can look in early 60s, 1968 parts books, and 850 Commando parts books and see what a dealer would have sold a customer back when the bikes were new, and it was one part number for the 99ss/650/750 engines pre #125871 and another part number post #125871 all the way into 850 Commando production.
Notice the spread of dimensions Ken quotes for the Commando, the difference closely matches the .040" that the Combat head was milled, but he did not say if that was the reason for it. IF the shorter Commando figure is for the Combat then you can see that there is only .030" (1/32") difference between the longer Commando spec and the shorter pre-68' pushrods, which means that with the manufacturing variables and quality between the old original and worn parts laying around and the various people now making valves, replacement seats, lifters and pushrods, you can go ahead and buy a set of new or used pushrods and valves, but betting on them fitting and working 100% as they are supposed to is a crap-shoot and is why you can only order what the parts book says you are supposed to then make sure they do work right anyway.
If you don't trust the books and manuals dealers used for two or more decades, then you should not trust parts taken out of an old engine that anyone could have swapped different parts into over the last 50 years, and the information that needs to be cross-checked more than any other is that from random people you don't know bleating on internet forums, including mine.