I have a 1997 gtp, a lot of modifications including ported upper and lower intake, 3'4 pulley on s/c, TOG headers with 3" zzp exhaust. Autolite 103 plugs gaps accordingly, Northstar throttle body with adapter, msd coil packs but im having a problem with the idle going all over the place, at times itl stay steady around 800 but other times it gets stuck around 1500 and doesnt come down until i put it into gear, has anyone had this sort of problem? any information is appreciated thank you!