I changed my htr core in my 85 Caprice classic. Probably the same in the 88. I
got to everything from the engine side of things. Didn;t have to mess with the
dash at all. Take out a lot of screws and mesh, and covers. Have to remember
where it all goes. Took me about 4 hours. Would have taken a real mechanic 1.5
hrs or less. Need more info ?