Basically, the first thing I did to my '77 was upgrade to a separate harness like Troy here is suggesting. Yes, it did make a difference. What I did next made the biggest difference. I installed a set of Iguana Motors Lizzard Lights. These are also what is on the Malitude, but I have had mine quite a bit longer. They are a lot brighter than stock, but they do put an audible load on the alternator. But it's worth it to me. You can really tell the difference too. The lines on the road really jump out at you. I love them. Here's the link.
http://www.iguanamotors.com/store_it...&category_id=6