71 valiant distributer, pertronix ignitor 1, and points... questions

Before you pull the distributor, take the cap off and take a picture of where the rotor is pointing and make note which cylinder number it was on the cap so you can put it back in the proper orientation...
Will I need a timing light for this job? I don't actually own one yet because I am on the lookout for a quality older one. I just ordered a dwell meter/VM/tach and it's on it's way in the mail.