is this at all possible weird

hello all, is this possible?firstly heres my settup, 440ci 68 A body,manual 4 speed, 750 four barrel vac sec, msd streetfire,new o/e elec dizzy,coil,leads..........car starts,somtimes bit reluctant kicks back,flames thro top of carb, idles fine, runs real boggy under load then suddenly like a switch picks up, carb fine, plugs spot on colour.... < revs up real sweet when stationary, timed up twice and still seems to run advanced, bastadized number one spark plug,cut out ceramic bit,threaded in 10mm studding protruding into heads ,refitted plug, cranked by hand till piston stopped,checked rotor, bang on number one on cap,looked at balancer..............no sign of timing mark in relation to fixed pointer on block.................. can somthing have slipped? know the balancer keyed on but this odd, cheers in advance, nathan.

your half right... the inner hb is keyed on, the outer (talking stock dampner) has a rubber ring between the inner and outer rings... they can break lose and spin... just had this happen on my slant and upgraded to a Romac SFI one...