Wiseco need to be measured and bored to fit each piston/hole. I remember being surprised at the variance during my last Wiseco build. All others I have built in the last couple years have been CP, which have very close production tolerances. I don't think the last set had more than 0.0001 variance. If you are running pump gas under 450 hp, stick with the spec. If you are going to run E85/116 and beat on it, run a half thou more. Same deal with ring gap, on the loose side if you are going to punish the motor. I build all my personal stuff with a bit more clearance, but I don't mind a noisier motor. My L-series in the 240Z is noisy when cold and a bit of a oil burner, but running C16 at the track, it's nice and quiet...
