Mercury Motorsport said that the PFC they used didnt need the engine harness to be cut/modified at all, BUT, a guy from Japan that did Goldzillas car said the GTT plug doesnt fit, ALSO, the R34 GTT neo engine has infinatly variable VVT where the R33 engine has it only on/off. SO, not sure what MM did about that, but they wouldnt share...its a secret