'66-ish GM water pump disassembly

Maybe more CM than GRM, but thought I would get more hits here:

I'm trying to disassemble the water pump from my '66 Impala in hopes of rebuilding it and reinstalling it but I can't get the pulley mount off the shaft. You can see the bearing puller (which I cranked a bit tighter than I felt comfortable with) and some heat (not red hot, but hot enough to start smoking) with no luck.

So two questions remain:

1) is it supposed to come off?

2) does it NEED to come off? In other words, which way does the shaft push out of the housing? If I put it in a press and push on the impeller side, will it come out?

I tried an internet search, but the pumps I've found aren't quite the same (most of the ones I'm finding have a removable panel enclosing the impeller section, this one does not).

It might take a press to get it apart, not sure though.

On a related note, this site has NOS water pumps for 230/250 GM sixes http://www.langdonsstovebolt.com/

Price is reasonable at $20, in case you can't get yours apart.
http://www.langdonsstovebolt.com/store/#!/New-Old-Stock-OEM-Water-Pump-230-250/p/37085013/category=361513

you're doing it wrong, that should be part of the shaft and press out with it from the backside. never rebuilt one though, as chevy stuff is so cheap.

In reply to 81cpcamaro:

I have an O-vancedzone unit in it at the moment, but thanks. I really wanted to keep the original casting (I'm pretty sure it came with the engine new)

In reply to 81cpcamaro:

Awesome! I was hoping that'd be the answer!