i have a 2000 gt and i changed the plugs today it had the bosch platinums in it and i went to put the autolite 764 copper ones in and the thread is diff on the bosch and the autolites are diff the bosch ones have a longer thred so they would go in the cylinder better and the autolites cant be screwed in as far? now my car seems to run slightly off and isnt as peppy. anyone else had this problem and or know any answers?