PS pump which one to use?
Everything is 70+ timing cover, water pump, etc.
I would look into seeing if you can swap the 70 and later radiator in the 69 body... I've never done it, so I don't know for sure if you can, but I think it may be possible... We need someone that has done that to tell...
If the 70 and later radiator will fit into your body, then the 70 and later front engine parts (timing chain, aluminum water pump, p/s brackets) would be the easiest way to go as you have most of the parts already... Then run the 70 and later alternator brackets with a single groove alternator...
For the alternator, you need to match that with your voltage regulator... The 69 used the old solid state voltage regulator which I would run and use the old style round back alternator with a single groove pulley... The alternators will swap into either old or newer style brackets, just get the proper alternator brackets for the water pump you go with... The 70 and later used the square back alternator and electronic voltage regulator which will require a little wiring modifications to convert if it hasn't been yet...