Guys here is the cam instalation instructions incase you are having problems instaling your cam or deciding wheather you are qualified to do the job.

A2

If the cam turns or the crank turns you will need to align it. Here are the alignment instructions for A2 8valves

A3 8valve instructions

If the cam or another component slips you will need to align all the pulleys. Here are the instructions for A3 8valve

(sorry it's a bit crooked)