Why are some round and some square? Does one work better for the gas air flow. It seems the 2 speeds are the square more often. Is it best to match square with square and round with round? I'm planning on putting the 16 dellorto on a Korado engine. The korado intake hole is about a 16 and round. The dellorto is square. I think I'm going to grind out the dellorto intake to make it match. what do you all think? what will perfom best?