To go into detail a little further we had an aftermarket damper that looked great last year but the outer ring spun 180 degrees. Double check top dead center to see if the outer ring could be moving. An ATI damper is going on this years engine.
He is running a ATI damper but I would check 2 things..
check the zero and check the numbers on it to make
sure it fits his application(external or internal
balancing)... the only times I've seen where the bolts
came loose the balance was off or the trans was not
in alignment and needed offset pins... I've been
using the MP bolts forever and I use them twice then
put in new ones(mainly because the head will round
a bit)... I use a impact on them through the starter
hole but just give then a light rap a couple times
