318 poly crank in LA engine

So i should have started this discussion here. Long story. Bear with me.
Friend has 59 dodge regent,with an 82 318 la engine a previous owner installed. I repowered it,removing the engine and manual transmission,replacing it with a big block and automatic.

Jump forward a year, im cleaning up engine to install in my barracuda.planned to mate it to the ‘65 auto all nice and neat like.
So while discussing a flex plate issue in the coffee thread it came to my attention it has 8 bolt holes in crank flange.
Being 7/16” unthreaded holes
Its aparrently a poly crank and no register for torque.

I’m a little discouraged at the thought of the plan Falling apart, will need to find a crank at the very least to get back on track.
There were offers of a flex plate that may work,and my parts guy has a line on something.
But that doesent solve my register issue with the torque convertor.
Setting crank up in my lathe shouldnt be a problem,and boring it for the stub on convertor should be easy. But if im pulling crank, i would be inclined to install a better suited one to meet my needs.
I really cannot believe this would get so complicated.

It was mentioned it may not work unless i have the correct transmission,a cast iron one.
So thats another thing to deal with.
Starting this thread in hope that others may offer helpful suggestions and for those that my have a similar issue. Or may for some reason want to install a poly crank. And the problems they need to overcome.

Thanks in advance.