Not to be disagreeable, but... The timing sets that are made are all made with a given amount of error in them. It's called manufacturing tolerances. The chain has them, as does each gear. Theres a tolerance for the teeth on the gear, and a tolerance for where the dot, or circle, or triangle is, and for the groove the keyway and dowl pins fit into. Add them up, theere is enough just in the timing set to make it necessary to degree it. Cheap timing sets are MUCH worse.
Every cam manufacturer has different specs in terms of lobe centerline, and installed (recommended) centerline. Custom grinds put it where you want, not much else does. Most grinders do add some advance when they grind a cam, but it depends on the profile. They also have a spec for tolerance, just like the timing components. If you have never found anything off more than .5*, then either you are the luckiest machinist I know, did something wrong, or dont use MP cams, or a combination. Comp is usually dead on the recommended installed centerline, when the "dots" are lined up. MP cams are terrible. Crane is usually close, but no close enough for me to trust them to be dead nuts. The reasons one degrees a cam, is to eliminate the possibility of error from machining, or installer error, or set the centerline to something other than what they ground into it. It's kind of like gapping new spark plugs. If all was perfect, you'd never have to, but shippers drop plugs (as do installers) that close the gap, plugs are made with defects, and sometimes you want to see if a non-stock setting will make more power, or stay cleaner longer. Production engines can use production marks, that's what they are there for. For my engines, I want precision that the factory manufacturer marks cant give you.
For an example, I fixed a 383 for a friend. He had never driven a BB mopar, so when I heard the car running, and then went for a ride, he was surprised when I said it was terrible. Took the timing cover off in the car to degree it. Found the stock replacement timing set was marked almost a full tooth off. Then I degreed it. The MP resto 383 4bbl cam, was brand new, as the rest of the engine was. the cam was ground 6* retarded from where the cam card said it should be. Between the poorly ground cam, and the poorly marked timing set, the "dot to dot" method was 10* off. That was because the timing set was advanced 16*, while the cam was retarded 6*. the car had no cylinder pressure (110-120psi), and no power. Once it was fixed, the engine had 170 psi, and to this day amazes the guys that drive it. (it was sold, but when it was resold, it was in the description). Its the details that make some things work better than others. If this is no big deal, then by all means, keep doing what you're doing, but IMO, it's not the "right" way to do things, and will cost some power and drivability.
