The clamps do not really need to fit the grooves though. the intake rubbers on the engine side seem to be grooved so the lip of the carb pops into them. The clamp just provides extra snugness. I have yet to have my carbs come loose in anyway but then I use the airbox. Maybe if someone is doing stacks or pods, then it might not work as well but then they should be somehow supporting the rear of the carbs anyways.