Ya, I heard that aluminum react with steel. something about electrons not matching and causing galvanic corrosion, which is rust I think.
Let us know how it goes though. I can talk you through the timing bit. That is easy. I would set everything at 0, on the compression stroke first, before you start the tear down. It is hard, but it's not a nightmare. I had to replace the pulley on mine. eveything was bad on mine. I spent $1500 on parts this year alone. $700 on parts the year before. Ya, your way ahead of me. Don't worry.
