I know this sounds simple but are you sure the belt is tight enough.
Should not be shaking between anything unless a bearing is seizing up
But it sounds like you ruled that out.
Also is that a straight edge in the picture showing your alignment is good
Between w/p and alternator ?
What about crank pulley alignment to either of those ?
Throwing out ideas.
Sure looks like your belt isn't tight enough. Why do you have the extra thick washer on the alternator bolt? Could the belt be flopping around enough at higher rpm's and hitting that bolt head? Also take the belt off and check the 2 pulley alignments with a beefier straightedge.
I see the extra washer under the bolt head to the alt bracket.Washers are there because of spacing everything out the damper is a ATI . are you saying check the alternator and waterpump pulley alignment or crank shaft and alternator
Wonder if those washers are pushing the bracket causing misalignment.
Then I would think that is your problem unless something got bent when pulling the motor? Are you certain that the balancer is seated all the way? Compare the thickness of both balancers.Funny this is the same setup I had on the 440 before I pulled it to replace it with the new motor only thing different is the ATI damper
Then I am thinking something alignment wise has changed.Funny this is the same setup I had on the 440 before I pulled it to replace it with the new motor only thing different is the ATI damper
Here's what the belt looks like with engine running
Another thing. Did you file the one offset hole on your original crank pulley to an oval to match up to the new balancer?