I grabbed one, looks a lot like the McLeod bolt on weight design that allows both internal or factory external. I'll spin it on the next build, I will a Fidanza alum and a Ford Racing that need true zer, won't take but a few minutes minute to bolt this one on
That being said, I wouldn't worry about using it in either configuration. Correct it when you balance the engine, or match balance it to what you pulled off, easy-breezy