[V8] Heater Box Removal....AAGH!!!

[Klein, Nathan P]

Some of you may remember that I heard a "POW!" from my dashboard a
couple of weeks ago, followed by smoke coming through the A/C and
defrost vents and antifreeze on the ground.  Got in there this weekend,
and sure enough, the plastic heater core inlet had shattered or
otherwise disintegrated.

I spent a couple of hours Saturday and Sunday trying to get the heater
box out.  Of course it was triple-digits outside (in the 70s and 80s the
rest of the week).

Anyway, I've removed all of the obstructions to the box (hoses,
windshield wiper assembly, etc.) and can only lift it up a few inches.
There are some vacuum lines on the left (if you're facing the heater
box) that look to run into the firewall.  Possibly that's my hangup?

Either I'm missing a step or I need Herculean strength to get the box
out.  I don't think it's the latter.  It sure feels like it's still
attached to something.  How do you make the box clear?  Surely you don't
have to disconnct the low-pressure A/C line.....

Also - should I go ahead and change the hoses to the heater core?

What to do?  Any ideas?  I've got to get her going again...

Thanks in advance!
Nathan