( screws -4/40 x 1 1/2" fillister head ) ( center to center = 27.43mm/1.080" ) for O.S. .18 CV RMX and other equivalent motors Wrap-to-center 25°up / 17° down header pipe *! (5/8"od tube) (this header puts the pipes right behind the motor, the carb. may need to be adjusted to allow this header to fit)