julies up to 2003 are low pressure systems,as hs11/33 are,so the levers are compatible and the power(julies had none though)stays the same,if not increasing,only the pad travel is different,but thats adjustable with the tpa.
julies after 2003 are high pressure(hp) systems,the master piston is smaller and the hose is reinforced,less pad travel,no chance for a hs lever to work.
ran a 2000 julie with a 05 hs lever for a while,the hs lever was more powerful in braking force than the original one(4 fingers though)
hope now it makes more sense...