I sold my sm 420 and im putting in a T5, i know the length of input shaft was 6-1/2 inches.but Im having trouble finding a dimension for the splines from the pilot bushing end. I think my T5 shaft the splines are bottoming out on pilot bushing. The T5 trans face to end of splines is 6-5/8 The old 420 i believe was 5-5/8