Here you can see the contrast between the old and new secondary metering rods, primary metering rods, and primary jets (shown from left to right). In order to motivate the air/fuel charge, the primary metering rods were downsized to 0.044 inch, and the secondary rods were waned down to a CV size. The secondary metering rods were hung on an L hanger. Theyre designated from B to V, and each consecutive letter means the rod holes are drilled 0.005-inch lower to plunge the metering rods deeper into the jets. Sean chose a 0.075-inch primary jet, which slightly richens the mixture over the stock calibration.