I have a Professional Products 70mm tb and there is no hole in the throttle blade. I have had a surging idle problem since i but the cam in and new throttle body and egr spacer. If i hold the rpms up for a second or two then let off the car idles fine, for a while anyways. My question is if i drill a small hole in the blade will it help fix the surging issue? I have heard of people doing that to cure a surging idle. What size hole should i drill? Has anyone had a surging idle problem like this before? I have checked for vac leaks and found none and tps voltage is in spec. IAC is new so any tips would be greatly appreiciated. Thanks guys.