for ease of setup fit 4efte gtt loom and ecu , map sensor , knock sensor , 4efte injectors , dizzy , coil/igniter there very strong engines !!!! im boosting a gi block in my gtt 10/11 psi no problem i ran more for a while to but its a bit risky i would get the 2mm gasket to lower the comp a tat ( its always safer ) you can always source 4efte pistons in the future and get them pressed to the rods :) as i have done now