I am currently putting a later internally cooled 71 in my old girl that had an old external cooled motor. Radiator hoses don't fit, heater hoses are different. Will match some up at work tomorrow but just thought someone may have done this and might have a few pointers?

Don't worry!  Got it working, and managed to take it around the block tonight.  It's running great, but has an odd knock that I can't place.  Might be clutch/flywheel, currently can't be exact as the noise from tappets that I haven't adjusted is travelling everywhere!