I just purchased a distributor from Ken for my 70 GS 455. He carefully reviewed my engine specs, sent several emails to confirm what I was looking for, curved it to my cam-setup and installed a Pertronix . He also added the ability to adjust total mechanical advance and an adjustable vacuum advance can so I can fine tune for different fuel etc. He will set up all my carbs and distributors moving forward and is really responsive and easy to work with. Thank you Ken!!