These can be mounted to monitor the crankshaft pulley (look for a small unit with wires going to it - around the pulley) - OR sometimes they are incorporated into the distributor unit.
It might be good for you to ask your mechanic. He should tell you.
It also seems that you should purchase an 'alldata' subscription; or purchase a Hanes, Chiltorns or Factory manual. To do any actual work and get it done right - you need to have access to numerous photos, illustrations, and diagnostic advice and suggestions. A manual provides this.