New torque/ did we screw up ? 360 magnum

The 360 balance weights are normally on the drive face of the convertor. Weights on other parts of the convertor are usually for balancing the convertor itself, ie get the convertor balanced to 0 and then add the appropriate 360 "external balance" weights.
So to make the convertor neutral balance, you need to knock these weights off:
20200722_161629-jpg.jpg

Additionally, I hope your "old B&M flex plate" isn't for a neutral balance engine.
5.9 Magnums are not neutral balance. They are externally balanced, but the balance is different than an LA360. People generally use the 5.9 Magnum flexplate, which is weighted, with a neutral convertor by oblonging 1 of the holes in the flexplate.