issues

[vex]

I'm curious, do you have a wideband? I would bet that you're running rich since the 255 is dumping fuel in probably at a higher pressure than stock. If the 550's are in your primary location you're getting too much fuel in. If the 720's are in the secondary you only compound the problem when you get in the upper rev range. If it's reversed, you have way too much fuel there. And it only slightly begins to tapper out when you open up the secondaries. In either case it doesn't sound like you have a way to control the fuel for the upgraded injectors.