: 79 DeVille Cpe 425 Engine tuning

05-15-04, 07:24 PM
After driving my DeVille for several years I am wondering if there's a simple way to add 30-60 HP's to the standard 425 engine. (280 Hp's is the standard?)
Read a few articles about engine tuning and as far as i understand, the simplest way is to exchange the carburetor and the manifold.
As I live in Switzerland and the local Caddy community is relatively small... I was wondering if someone can give his advice to the following questions:

1.) Can the original Rochester carb be modified? If yes what is the result?
Just ordered the Rochester carb book for further studies....

2.) There are rumors, if the AC must be removed permanently if the manifold is replaced...can anyone confirm....resp. is there a model that allows to keep the AC?

3.) What is the best carb and manifold combination and how many additional HP's am i getting out of that modification?

4.) There a rumors that a dual exhaust system will add more power? Have the standard exhaust system but removed the catalytic converter unit. Personally I believe that this has not much influence....

I do not intend to race my Caddy that has already 90000 miles on it....but would be nice to add an extra "bite" :D to the engine without reducing the life expecation if possible... of course it is also a budget issue!

Thanks for your help and looking forward to receive your comments....