I did the external voltage regulator conversion on my Spirit R/T, and it seemed to be working fine, other then the fact that I am about to replace my regulator for the 3rd time in a few months. At first I had a Standard Ignition one in, and it crapped out after a couple of months. Then I put in a Transpo adjustable one, and it crapped out after a week. So now I'm going to install another Standard Ignition one. Hope that crappy parts are my only problem.