I think that TH and I are on the same page here. I cut mine to aim directly at the back of the valve ... just like the stock setup because I'm retaining the use of the stock injectors. I guess the better question here is who is aiming at the center and using the stock injectors? If you are, you may not be helping at all and may be hurting your fueling atomization. Now, if you have and you are using the oval port injectors, you are accomplishing what you thought you would when you cut the heads. The key variable here and what Terry is pointing out is that the injector spray pattern is different in the two heads and most people that use the oval port heads and retain the split port injector location reuse their split port injectors.