Like many of you, I've noted that my stock alt doesn't able to keep up with lights/heater/wipers/etc. I've been tempted to just install a higher amp alternator, but after reading lots of posts, reading the book "managing 12 volts" talking to wranglernw, david dearborn, to the guy at madelectric, and a few others, I decided to first make sure that my stock charging "system" was working properly. Turns out it's not a question of the alternator, you've got to make sure the system is up to snuff. My 60 has a replacement engine, done by the PO, not a real clean install. I've never been sure that the wiring and emissions were done right. To simplify things, I purchased David Dearborns charging system upgrade wiring. Really nice product! I can make cables my self, but his are awesome, and more importantly I got more cables than I expected! So, first improvement is that I now have all of the right ground wires! Plus, they are so big that any voltage drop is negligable. Second improvement is that I added a 2 guage wire direct from the alt to the battery positive. I kept the existing wiring intact. (I fused this new wire.) This idea is direct from the guy at madelectric. My system voltage stays a lot more stable with this wire in place. Third improvement is that I used the slee headlight harness for my higher watt bulbs, but I ran the hot lead direct from the alternator (again a suggestion from the mad guy). This way the bulbs get 14.5 volts and run brighter. The relay harness takes a load off of the rest of the OEM harness, which allows the heater/etc to run better - again further stabilizing system voltage. Overall impact is very noticable. Used to be that at idle, I had 11.5 volts with lights on. Less with heater/wipers/etc. Maybe got to 12.5 at higher rpm. Now I get 12.5 - 13 volts at idle with lights on, and barely less than that with everything running. I have a solid 14.5 volts at higher rpm. It's pretty cold in Seattle right now (for Seattle anyway) - but the effect of my new system is that my cruiser starts super fast and easy. No question, this new system is notably better at colder temps. My alternator was always putting out 14.5 volts (over 1000 rpm) it's just that my poor electrical system didn't allow that juice to get where it needed. Too much resistance.