How much interchangabilty DeVille and Eldorado?

[fasted55]

I have a 1979 LeCabriolet and as I search for parts I wondered how many are interchangeable between the same year DeVille and Eldorado?  A few examples; the coolant overflow bottle?, the winshield washer fluid bottle?, the heater core?, even the climate control?, all appear to be the same.  I would imagine GM shared many of the parts?  Thanks, Ed

[TJ Hopland]

For 79 the Eldorado was a much smaller than past years all new body.   Because of that I would think many of the items you mention may be different. You never know tho by that time they certainly would have compromised the design to save themselves 3 cents so who knows.  The heater core is installed from the inside the car on those where I think it was still outside on the RWD cars.  Climate control may be the same because I believe 79 was the only year the Eldo had the mechanical control.  80 they went digital so you would not think they came up with a 1 year 1 model system.   76-79 Seville also had a lot of unique to itself items.  80 the Seville was the same body as Eldo.   77-80's the rest of the cars were very similar.  The Brougham was the same till 93 ish.

I checked my pictures and don't seem to have an overall good underhood shot of my 80 and we got a decent snowfall going right now so I don't really want to go out and brush off the snow for a pic.  I will try and watch the thread and if you don't get any answers I can go take some photos underhood so at least you can compare the locations and guess. 

[Michael J. Cascio]

I can almost guarantee that all of the mentioned items will be different.  Different platforms.  Different family engines, etc.  items may look the same to the naked eye (ex. climate control face) but its mounting holes will be different.  You may be able to salvage parts from it though.  Washer & coolant bottles will most definitely be different.

[Eric DeVirgilis CLC# 8621]

Agreed with Michael. I believe very little compatibility exists between an Eldo/DeVille for the year stated and for most the parts you've listed. Possibility for the CC unit- just possibly.