Hello all! Just a few questions about parts and upgrades for an '85 C20 Scottsdale with the 350. My biggest question regards the HVAC system. My Scottsdale came with A/C which still works and blows cold and hasn't been retrofitted. My heater controls only have 3 settings: Defrost, Heater and A/C. I was wondering if it's possible to upgrade that control unit to the Delco #15-71268 that has the Economy settings and the different levels of A/C, like Normal, Hi and Bi-Level. ACDelco says it will fit in my vehicle, but doesn't say anything about compatability with upgrades. Another question I have regards my dome light. This is minor, I realize, but the dome light doesn't work. The fuse and bulb are both fine. The light won't come on when either door is opened. Is this a bad ground or loose wire? Has anyone else had this problem? I can't seem to figure it out. Also, does anyone else have problems with their intermitent wipers? Mine work perfectly on Lo, Hi and Mist, but won't work reliably on Intermitent. Any tips there? Thanks in advance!