I have seen about 5 IC setups including my own with the kind of hose. The only reason people THINK they have to use heater hose is because its coolant rated. The thing is the coolant in an IC system is never going to get even close to as hot as the coolant running through the motor so it won't matter. It's true that it's not as flexible but It doesn't kink and that's what 90 degree elbows are for. But I guess to each their own.