Magnum 360 to 904

Might be a stupid question, but i'll ask anyway:
LA 360s are externally balanced and 360 Magnums also but still there's a difference. If i am understanding this correctly when i pull my LA360
is there going to be a balancing issue with the weights on the converter and flexplate or do I just need to find a 727 flexplate and trans?

Any input is helpful.

Thanks,


.....................................PETE...........................