Flexplate is not fits the torque converter

THE ONLY OTHER EXCEPTION is if you have paid an engine builder to add weights to your crankshaft to balance the 360/ Magnum within itself. In that case you want neutral balance or internal balance components such as converter / flexplate

There are basically TWO schemes used over the years. The older LA used weights welded to the converter, but in a "swap" you can buy aftermarket weighted flex plates in order to use a neutral converter----which you appear to have
1. No weights to my crankshaft
2. No weights to flexplate
3. Looks like I have to buy the third flexplate but with the weights. (or can I add the weight to one I have?) Please help to get the right one (TCI recommendation was wrong)