After info on fitting a msd crank trigger to a 360 magnum & working out t pulleys

How much up & down play is there between the intermediate drive gear/shaft and the distributor? On my big block, I had to add a collar to the distributor shaft to keep the intermediate gear from moving up and down too much. Before adding the collar, the driven gear/intermediate shaft would ride up and down on the cam's drive gear causing accelerated wear on my bronze gear and allow the timing to move around like you are describing. The collar eliminated the intermediate shaft's excess up and down play, stabilized the timing and reduced the wear on my bronze driven gear.