Magnum flex plate 904 vs 727: identification?

It seems like the magnum flex plate topic is voodoo...

I'm just going to assume that I have a 727 diameter flex plate since they're presumably more common. :(

I just called Performance Automatic just to see if they had the right flex plate and the guy knew nothing about Mopar flex plates...they didn't even sell them (despite offering quite a few choices for Mopar transmissions).

If I'm reading the "Magnum Swap" page correctly, I will have to buy a standard Ram/Dakota Magnum Flexplate, then get a torque converter that is weighted specifically for a Magnum...and there's basically only one shop in the whole world that will make one of these?

:wack:

How will I know if the diameter of the stock flex plate will even work with the 904?

Can anyone generous soul offer any other ideas?

Thanks in advance!!
-Mike