hi i need help! i am looking for wheels for an 88 firebird w\ws6 performance package on it. The wheels on it are 16-8 front and 16-9 1\2 in back. all wheel companys say they do not have wheels for this because of backspacing. does anyone know what backspacing is needed for running 17\9s on all four coners and if i need a +offset or -offset. Also anyone like the edelbrock 409 wheels on firebirds. Thanks dave.