Hey buddy,
= If its any help , I build alot of strokers at my engine shop. The PP balancers for sbm use the same part#. The difference is they have changeable
weights that bolt to back of the balancer. You defenitley have to use the correct weight. It'll tell you in the paperwork wich part# to use. I think its 900something.
= The cast Eagle cranks are set up for ext. balance.
= I would think you should have a weight on your
converter aswell. Ive got several bad reviews on Bosshogs, but havent had 1st hand withem.
= 8 1/4s are pretty tuff. I have built and heavily
abused several of them. I would check axle runout,
and wheels for warpage or proper balance.(none of this concerns shake at idle though) So yeah you may have multiple issues. Maybye the carrier brg. preload has been set way to tight? hope this helps