Tolerance for Static Blade Angle of Axial Turbo Blower

We are replacing the static blades of an axial air turbo blower (3000 rpm) with new ones. In OEM drawing we find tolerance for clearances etc but not for blade angle. When asked they advised to follow the drawing. For example blade angle of different rows are 1^o30', 2^o30', 3^o30' etc. we adjust and measure this angle with the help of a bevel protector having least count of 5' (1/12^th of a degree). Adjusting the angle exactly same is very difficult and we feel that there should be some tolerance (+/-). Can some one have experience in this field and guide what should be the allowable tolerance for blade angle.