Art Carr Flex plate.

So I got a 1978 Mustang with a 1975 302 with a II C4 automatic. The flexplate is stock 28 OZ Balance. I want to put a 1991 5.0L H.O engine in the car. I searched our Forum and I am still a little confused.

What I gather:
-I need a 50 OZ balance flex plate.
-Art Carr makes one.

My questions. Is this a 100% bolt in deal? What starter will I need? Stock Mustang II V8 starter?? Someone mentioned needing a mini starter, someone else mentioned grinding stuff If a fabrication hat is required, I would just as soon have my flexplate re-balanced, If the Art carr flex plate is a bolt in, I would spend the money to make it easier. If we get a 100% answer out of this round we should make this a sticky!!!!
(we currently have two pages of conflicting information)

https://www.artcarr.com/merchandise/details/4/313.acpp

The guy at Art Carr says the stock starter will work?