I have a Shimano Alivio crank on my 2006 GF Piranha and have the chance to buy a used but very good condition XT crankset model 750 with a UN72-E BB. I won't be able to use the bottom bracket because it won't fit.....so here is my question. Are the alivio and xt crank arms/chainrings interchangeable? I'm only asking this because of the cheap price that I can get on this crankset. Thanks in advance.