Yes the can moves the plate which does alter rotor to cap alignment when it fires (RP) and centrifugal advance does not. when you pump up the can it changes RP and also greatly increases the reluctor gap & if you are at .008" at rest then that is OK & either one out of whack or a combo of both can cause it to act up. fix the wiring/set the reluctor gap at .008" with a brass gauge or just get it close but not touching & it might be slightly closer at the bottom so eyeball it good. On RP You are at an advantage cuz have the pump at your disposal. turn housing till the magnet is dead even with a tooth & lock it down & make a mark on the metal dist housing outer top perimeter rim just below where the cap seats for where it is clocked (confirm that the springs are retracted all the way which they should be but the slots could be gummed up so twist the rotor back against rotation to confirm) then replace the cap & make another mark on the rim vertically inline with the cap terminal bulge next to the 1st one then remove the cap for easier viewing & see how far they are off then pump it up & see how far it shift away from an acceptable alignment. RP from the can shifts CW on a BB and CCW on a SB & it shifts .024" around the arc for every degree of vac adv (see the # on the bottom of the can arm). the cap terminal width is .214" and the rotor terminal width is .244" & you want them in close proximity & also there is the radial distance from rotor tip to cap terminal and when the combo of RP and radial distance becomes greater than what the available voltage can jump then it will misfire (+ the reluctor gap issue potential). if you need to change RP position or increase rotor tip dimention holler & I will give more info & 3 or 4 options for that.