I'm pondering my thoughts...what about changing out your standard SR20 head to Roller Rocker head? I've got a RR head an block ... thinking abt swapping heads on my p11, b4 i install a SR20VE motor. i am pretty sure the power/torque will be somewhat increased initially,noticeably two heads carry different stamped numbers one 2J200, cant remember the RR # 54** but i think it can be swapped without any fuss as they look kinda identical, also i got the ECU & harness for the RR head an block, it's from an Avenir sr20de ,the maps on it look a bit higher in numbers for fuel and ignition as oppose to the 1999 jdm p11 primera ECU that i got on my motor originally i tried to hook it up but i keep getting MAF fault code evert time i try to start up anyway...comments, suggestions, advice are welcomed