Harmonic balancer questions

[shifty]

I'll start this off by saying: I know the purpose of a harmonic balancer, but that's as far as my knolwedge goes.

In an effort to "better" my truck and restore the original engine, I swapped my L6 this weekend. I solved most of my problems - like removing the threaded oil pressure tube someone loc-tite'd into the block, swapping heat sensors, removing various parts, doing a partial rebuild on my carb and installing a new clutch.

I'm having one big issue though - the spacing o nthe new harmonic balancer is different and I need to use the old one or something. I'd like to know:

Should I just go to a junkyard and find a new alternator and fan assembly or should I yank off the existing harmonic balancer? What can the veterans tell me about doing this process the right way?

So you see what I'm talking about, I have pictures! I will show you the differences and whatnot.

This is the HB on the new motor, notice the gap between the belt grooves; it's about 3/4" wide:


This is the old harmonic balancer, buried underneath that gunk, you'll see the gap is about 1/8" wide between grooves:


If I use the fan assembly the "new" motor came with, the HB and fan pulley don't line up at all. See:



Not to mention - the bolts for my my cooling fan assembly don't fit on the "new" engine parts.


Bottom line: I'm either looking at :

1) Hitting a junkyard to find a proper cooling fan assembly, proper alternator or alternator pulley and finding a way to space out the cooling fan pulley from the motor

or

2) Removing the "new" harmonic balancer and popping on the old one.

Do I have other options? What do you suggest?

Does anyone have tips (for future reference) on things to watch out for while pulling an harmonic balancer? What is the general process? Should I rent/borrow a puller from the local parts store?

TIA.