1- Yes the truck pan is rear sump , the car pan is center sump
2-Yes , truck mounts are different
3-no really common , early 70s & late 60s rads will swap in , from B bodys & E bodys , up to 74 in e body & up to 72 in B bodys
4- not hard there are after market ones or you can adapt ones from later year cars
5- hard to say , not sure what you got with the engine , 100 amp alt will require different mounts etc to go back to 60 amp factory alt
6- started to get you car on the road ... congrats
7- could be ... I am
8- keep it warm & dry , put some oil in the cylinders , keep the mice out , rotate it from time to time
you are welcome
Neil