I am new to this site so sorry if this is a topic that has been covered before. I just bought an unmolested 88 LX. My first mods are going to be an exhaust and pulleys. My question is besides weight what is the difference between March's aluminum and steel pulleys? The steel ones are only 49.88 through summit while the aluminum are 139.88. If there is not much difference I would rather save on the steel ones and put the money towards something else.