Howell Steve wrote: > If you are using a 3 1/2" cylinder already, you may not need to worry about > it. It's > the 1 1/2 to 2" cylinders that usually just have 1/4" ports. I believe Ron > said in his book you want at least 1/2 ports all the way around. Consider the possibility that the larger cylinder may need more volume that 1/2" ports will provide.