So the ones from Case are the metric ones? I would be tempted to look into some flat face couplers from the construction industry, keep things a little cleanerTo get the high-output fan speed to it's max you will likely need 3/4" couplers. I got by with 1/2" for a year but couldn't get max fan speed until I switched. Have to change the block the couplers mount to on CNH. I would go pioneer instead of those stupid metric ones that are impossible to hook up.