All depends on your goals, fuel type etc. be prepared to provide that info when shopping tuners. If you’re “FBO” with upgraded turbos and ALL maintenance is good. It’s down to the fuel system really. Port injection and controller if going full e85 or an hpfp overdrive or even a methanol injection kit. Without any of those just the low pressure fuel pump upgrade should support around 500whp on an ethanol mix. You should also get yourself upgraded coils if you haven’t already especially with misfires showing up.