I just wanted to thank the board for all helpful info, good and bad. I have a 71 Skylark with a 350 and a 4 barrel. I have read over that last 9 months the pros and cons of the Pertronix units. I read with interest in these units and have recently visited other message boards. It seemed that 50% love these units and 50% hated them. I had the chance to get a lobe sensor unit for less than half of new cost off of ebay, and it was new in package. I was hesitant about installing this unit, as it sounded that if you didnt get it right the first time, it would burn out the unit. While I want to report that Pertronix has another satisified customer. I was hoping that I would pulll the points and slap in this unit and that would be it. That was high hopes. I did all of the preliminary testing of the existing ignition system. Ohms of the coil, voltage to the coil, 1.6-1.8 and 9.5 respectively. Per the instructions this should be good. Not so much. While I will cut to the chase: If you install this unit-expect a little more than slap it in and kiss it good night. This is what I have found and was this is the info that I was looking for while viewing all of the message boards. You need a full 12 volts to the positive side of the coil, expect to increase the plug gap to about .050, get rid of the old cap, rotor and plug wires and upgrade. While your at it you might as well replace the plugs, your there just do it. After I installed the unit, the motor ran rough and would just cut out. Per the instructions connect the red wire from the unit to the battery. It ran better but timing needed adjusted. Ran a new wire from the fuse block to the coil, it was convenient as on the block was a male spade marked IGN. I left the resistor wire in place(disconnected from the coil) and capped it so that in the future it maybe used if I need to install the points. I adjusted the timing, ran much better. Drove it to the parts store and picked up new AC Delco plugs (R45T, per the mechanic at work), Accel super stock 8mm wires, Mallory performance cap and rotor. I installed all of these with the new plugs gapped to .050ish, the motor is so snappy, it probably has to timed again, but it runs great. I hope this will help others trying to decide if this will be a wise and beneficial purchase, I would reccomend this upgrade. Though I will keep the old points in the trunk or glovebox like everyone else. I hope this was the correct place to post this, if not let me know. Also I want to appologize if this is to long, but I felt I needed to add my 2 cents and could hopefully help someone else out.
ps I love this site with all of the great info that is passed along. I have not posted alot, but I bet I have read atleast 25% of the posts on here. As not all applies to my interest. Keep up the great work Admin.