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1983 Coupe Deville engine swaps

Started by DFuzzy1, February 13, 2017, 01:08:41 AM

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DFuzzy1

Has anyone swapped a 7L(425) into a 1983 Coupe Deville? I am looking at buying the 83 with a seized 239?(owner wasn't sure)and already have a 78 sedan Deville with a running 425 that I would like to swap in.
Thanks

Scot Minesinger

The modified chapter may have done that.  BTW, great way to turn a 1983 Cadillac (fuel injected) into a wonderful car.  The 425 engine (carburetor) is heavier and far stronger than a 4.1 or a 239, so transmission, suspension, rear diff, drive shaft, fuel lines, fuel pump, and etc. will be impacted.  The 4.1 is mounted close to firewall and the 425 is closer to radiator - so frame mounting mods to deal with too possibly.  Further there will be some electronic mods/interface with dash, climate control and etc. to deal with too.  Not a quick drop in, probably not economical, but so worth it if you like driving your Cadillac.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

TJ Hopland

The 425 is the same externally as the 368 which was an option for that body in 80 and 81 so the basic fit should not be a huge problem, back in the day you could just find a donor car or order what you needed, today that may be easier said than done. 

If it currently has the 4.1 252 Buick V6 I think it may be a little easier because that had a carb, it was computer controlled but still less complex than EFI.   \The standard engine for 83 was the 4.1 250 V8 which had the DEFI (TBI) fuel injection so there will be more details to deal with.    Optional was also the 5.7 Olds diesel which had no electronics at all.
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason