YOUR RUNNING LIKE A SCARED CAT AND MAKING WRONG MOVES!just calm down,i just fixed this problem on my 69 r-r 440,mobody can tell you ,i had to figure this out,my car has a 73 cast crank 440 viabrated like hell,what i did was fist wnt to 440 sources websight,looked at his explanations of diff balancers,made sure i had a cast crank balancer,then had to figure out that chys only balanced ther engines by the converter(by putting weights onem)since there are so many aftermarket converters out there,thy had to figure somthing else ,so b&m makes the flexplate wit the bite out of it,you need that with a non weghted converter,plusthe idiot on mine didnt have any dowels on the motor,had to get them,now the thing is butter,so use the b&m (bite out)plate not the one that lookes like a bow tie,any o balance conv you want and make sure youre dowells didnt fall out,cause you cant just hang the trans on the bolts,and you will be fixed,if you want to get a new cast balancer get it from 440 souse,tell him you have a cast motor,thats it,i telling you this only cause you said it ran great before,engines that run usually never go bad sitting on a stand,see you at mmw-jeff-314-303-2044