Has anyone replaced their stock single carb manifolds with the dual carb/split exhaust manifolds from the '41 or '42 Buick? I want to know if it's worth it, they are hard to find and expensive, plus Buick boasted only a 10 HP gain. Can anyone tell me their experience? Also... they were only installed on the 320 ci. engine, do they even fit the 263 ci?
thanks.

Buick had a dual carb set up for the 248-263- and the 320 inch engines. I ran the dual carb set up years ago, and was not that impressed with it. I now have the dual exhaust manifolds on my 40 and put dual exhaust on it ,and the 263 intake with a big series carb, and it runs very well.The original system had a "Y" pipe , and I did away with that to run the duals.If you have a 48 up Buick, it is difficult to put the dual exhaust on because the left motor mount gets in the way.