My 904 pulled from a 318 question

I have a question to add to this conversation. If your using a weighted converter (like a original 360 or a welded 318) does it matter which flexplate you use? For instance if i weld weights onto a 318 converter can i use the 318 flex plate? Or do you still have to use a 360 flex plate?
The reason I i ask is i have my original 360 converter but my 360 flexplate got bent. But i have about 3 318 flexplates laying around.
flexplates the same, although there are a couple of different sizes of those also. the reason most do the flexplate instead of weighting the converter is so they can go from converter to converter without dealing with the weights.