Rotor changes timing, 123 running fine, but? Options

[mgphoto]

So my engine has been really running fine except for a miss that seemed to come on at about 3200 rpms. I'm running the 123 D Jet version #B switch and no vacuum connection to the dizzy. I've pulled the timing back to 26* and I'm using regular gas with an MMT additive to control ping. This setup has been working very well as I've been testing different brands of the additive for effectiveness.
The miss I've attributed to cap, rotor and wires. I replaced the cap and rotor and before replacing the wires I took it for a spin.
The miss seemed to be gone but the ping I had tuned out was back?
I hadn't moved the dizzy, I tightened the clips holding the cap but no other change.
So I pulled the cap and took out the rotor to see what might have changed.
The new cap was identical to the one that came with the dizzy, but the rotor not so much.



I suppose that could be a 2* difference in the rotor pickups?
I put in a rev limiting 5850 rotor I had in my stash and now no miss and no ping!
If there's an issue it will find me...