5.9L Magnum build with questions

NATIONAL FC69907

I’ve heard of the input shaft length needing cut down a little bit too? I didn’t have to on mine after checking the clearance though.
Awesome, thank you! Yeah, I’m hoping I don’t have to cut mine either. It’s the original transmission to the car and I’m trying not to do anything irreversible in the future if by chance it ever gets restored. I’m also thinking about the American Powertrain hydraulic throw out bearing kit. Any thoughts?