early a-body (64-66 cuda or valiant) exhaust - H or X

I will be having some exhaust work done on my car. I've researched all the benefits of adding H or X exhaust to your car. And of course, the differences between the two

But as a early A-body owner, specifically a 1966 Barracuda. Will it fit? That is the real battle

What is everybody else running and where was it placed?

And of course, pictures always a plus