You will get a noticeable amount of increased power in just splitting the exhaust. Adding a second carb will give you more power but it will be in the single digits where the split exhaust will give you about a 10% increase. In my case my '49 D30 230 cu in motor I added a second outlet but did not split the halves. This way I am still able to use my intake heat riser. I also did more for carberation, I built an adaptor and added a holley 94 2 barrel carb rotated 90 degrees. This way I only had to make 1 adjustment to the stock throttle linkage. You might check out the
www.p15-d24.com website. A lot of those folks use a dual carb setup and will be familiar with the tuning charcteristics
Jim
