P body it is time to settle up. Lets do this if you would please, take the dist before you ship it & clamp the lower shaft in your vise with a rag to protect the shaft of course & turn the housing till the magnet is lined up with a tooth and note the rotor position relation to the cap (which is the RP clocking) this is RP with no mech advance. now turn the housing just a bit CW so the tooth is now a bit to the left (CCW) of the magnet & this is/will be the tooth approaching the magnet in normal CW rotation. Now hold the housing rock steady still then twist the rotor CW (which is giving it mech advance) till the tooth is lined up with the magnet (like before) which'll be when it fires which is what you will see/be at with the light and the rotor will be in the same clocked position on the housing/cap terminal as it was before you twisted (advanced) the reluctor/rotor.
Thats the thing.. it will move BUT its not gonna move much.. and as you said.. the light will still show the rotor.. but if you mark the cap and start increasing the rpm.. the mech advance starts to move the rotor... the light still flashes at the rotor.. but the rotor moved in relationship to the mark on the cap... like I say.. the slots in the advance plate only gives about 16* of advance at the crank... 8* on the dist(or what ever the advance plate is set up for)
