Here are a few extra tips I've picked up from installing hundreds and hundreds of Pertronix kits over the last several years:

1. When installing the magnetic ring on the distributor shaft, check to see if it fits loose. If it does, apply a dab of silicon sealant inside before you press it on the shaft. This will prevent the timing from shifting when the ring moves.
2. Always use a small tie-strap to hold the wires down the the breaker plate. I see many failures from the wires rubbing on the trigger wheel. Once the insulation wears off, they are susceptible to shorting together, and to high voltage misfires. Instant death will happen quickly once the wires are exposed.
3. Make sure the wire ends fit very tight on the coil. A loose fitting will cause the unit to fail prematurely, misfire, overheat the coil, burn up rotors, pick your poison.
4. You MUST use a 3 Ohm internally ballasted coil.
5. You MUST use a volt meter to check the voltage into the coil with the key on AND with the car running. You want to verify that you have a 12-14.5 volts. More or less voltage WILL damage the unit, causing premature failure. DO NOT bother using a test light. Use a meter set on 20V DC. That's the setting with the dashes, not the wave.
6. If your car has been converted from positive earth to negative earth, recheck every single step of the conversion before proceeding with the installation. 50% of all Pertronix failures I see are from something that got missed. Use Barney Gaylord's site mgaguru.com to double check your work if you need to.
7. Read and follow the wiring diagram. Check it 3 times from different directions before turning the key on. Work your way from the key to the distributor, then from the distirbutor to the key. Take a break, come back, match the diagram to the car once again before you start it for safe measure, as its $80 in the trash if you miss one step.
8. Feel free to grind away part of the aluminum mounting bracket if it makes the installation or service of your distributor easier. Just don't carve into any plastic, and don't allow the bracket to get too hot while you're working on it.
9. You can trim the wires to fit your application - they're made WAY too long so they'll fit a miriad of cars that share the same distributor.
10. If you need to call Pertronix for technical support, do it twice. Hopefully you'll get 2 different guys on the phone, and you'll probably get 2 different answers. How do you determine which is correct? Tough call. Pertronix doesn't have an electrical engineer on staff. Those guys are salesmen - even the guys who answer tech calls. They have to answer calls on all makes and models of cars, so they likely won't know anything about ballast resistors on a Midget or what voltage range a Lucas generator puts out. Get a real answer from a local shop, online forum, or a specialist who can help accurately!