jeffy:
Just a reminder that my current (and your proposed) Weber setup does not have a provision for a thermostat.  I have ended up putting one into the upper hose and blocking off the 
oil cooler in an effort to try and get some heat into the motor.  
Jim
PS:  Danny said, after rebuilding my set of Webers, that he would never do another set... so, I hope you are buying new.
       FYI:  My current motor is a Dart (4.25") iron block with Dart aluminum heads.  The block has four bolt mains on all of the mains and required a custom (Stef) 
oil pan.  I believe that AVIAD now makes a pan for this application.