Huh?
Is this an LA 360 or a 5.9 Magnum?
There is no "enlarging a bolt hole" with an LA, that's a Magnum thing.
An LA 360 requires the use of a B&M flexplate #10239 in order to mate an externally balanced LA360 to a neutral balanced 904 convertor. No modifications needed or holes needing to be egged out.
If it's a Magnum 5.9, yes- oval out 1 convertor hole on the flexplate. You'll see where and how much by holding the flexplate up to the convertor.
P.S.-
Take that "TEMU" hoist to the scrapyard and use the money you got to rent a real engine hoist from an equipment rental center on your way home. This could be your life you're messing with, do you really trust it? Obviously not.