Magnum 360 swap questions

So I'm just tossing around the idea of swapping in a magnum 360 crate engine into my car, and I've had a question arise about the flex plate. I know that I need an externally balanced magnum flex plate, and according to magnumswap.com, I can't use an LA 360 flex plate, but rather a magnum specific one. I found this one on summit:

ATP Flexplates Z-332

says that the outer diameter is 11.5 inches, and in my service manual, I...

Magnum 360 swap questions
Author: rcmaniac791