Don't dread it - replaced the core and box on my '66 and wasn't that bad.
Drain antifreeze, disconnect hoses yadha yadha and put duct tape on heater
core ends to prevent drips. Discount the heater louver cables first.
Remember their routing and placement as they spring straight when removed -
also a good time to lubricate them. The original nuts used on the heater
box studs that bolt to the firewall are "pal" type and aren't as durable
with a wrench as a regular nut. Clean the old paint / crud away and put
some penetrating oil on each stud. Work the nuts off back and forth. The
lower right corner is in a tight spot but still accessible with a box
wrench. Once all the nuts are off, the heater box (with heater core
inside) pulls straight off the fire wall into the car. You may need a new
firewall seal depending on its condition. I had a problem with the
aftermarket heater core being slightly thicker than the original Harrison
thus the original holding clips were useless. Ended up using foam weather
striping on the heater box were the core makes contact with the box and
used a blop of silicone on all ends to keep it in place yet allowed for
some vibration.
Hope it helps,
Krister
My heater core leaks. Any secrets out there to make this job easier?
Does the inner fender well need to come off? No AC. Dreading this job.
Larry Williams
