400 transmission options?
 

I am working on the truck in my sig. I got sick of adding a quart of oil once a week to the worn out 318. I talked my Uncle out of a 400 out of a 70 something Ramcharger. I was planning on rebuilding the old trans, but when I started pulling it down the there were a lot of metal flakes floating around in there. So rather than messing around with it I'm looking for a new tranny.

My question is what are my options. I want to keep it a manual and I am not opposed to moving to a newer trans even a five or six speed would be okay. I also realize that I will probably need to new tcase and everything else. I figure if its worth doing its worth overdoing.

Thank you for your help.