Ok,
I spent the last hour and a half searching but found nothing on the subject.
Mines a 1974 472, heater core is leaking badly enough now to be bypassed.
Anybody here dealt with replacement before?
Tell me what I am up against?
HELP!:crying:
paul

The factory shop manual could probably give you the best idea about it. There are a bunch of them on Ebay right now.
http://cgi.ebay.com/ebaymotors/1974-CADILLAC-SHOP-REPAIR-MANUAL-ORIGINAL_W0QQcmdZViewItemQQcategoryZ34212QQihZ022Q QitemZ350025280392QQrdZ1QQsspagenameZWDVW
I wouldn't bother with those Chilton or Haynes manuals. The heater assembly is probably similar to my 68, and it doesn't look too bad according to the manual.

Thank you! :D