alternator pulley

[green67cuda]

so...i finally went and got a later model alternator and voltage regulator...

but the pulley is tiny....how do i put the old one on???
it looks like it's all one piece

and what's the round cylinder nose on the pulley for????

 

[green67cuda]

ok...i just found out that it requires a puller.....now...can i just use the whole front cover/rotor from the old alt on the new one, or is the field where the extra output capacity lies??

seems to me that the stator is going to be different, and the fields would be the same, except that the newer one is an isolated circuit