A couple of days ago KSC and I did our best to mark where the hole for the heater air pick-up should be drilled in the lower cowl. I drilled a 44mm ( one and three quarter inch ) hole in the lower cowl with a hole saw. KSC and I nervously attached the lower cowl and thank goodness the hole is in the correct position. I think the pick-up tube is a little short, ( maybe not ) so I'm ordering some longer tube.