My Mustang is a 1968 302-J code correct engine, factory air car. Got a NPD belt mark on sleeve (Marti Auto Works C60E-8620A sticker) (NPD Sticker on sleeve is marked 8620-52) the sleeve is a Motor craft sleeve marked JB 470. The belt is marked C60E-8620A This belt is TO SHORT will not fit with tensionor loose. HELP!!!!!!!