Blueprint 408 cooling system questions.

You already have the radiator, so it's a little late, the '69 cast iron pump is 3/4" shorter than '70 and up pump. I am trying to get a compatible set up right now for my 418. I think that I will have enough room with the Cold Case Radiator, viscous drive fan and shroud when using the '69 style Milodon pump. If it all fits, after engine start, I will be taking all of the advice given in these posts.
Chrysler Parts, used. (old)
2863216 18" fan
3462108 Viscous Drive
16251. Milodon Pump
Do not have shroud yet

From timing cover to end of drive is 7 3/4".