Anyone have the MSD Streetfire HEI and purchased the spring and bushing kit for it recommended by Summit (p/n 8428)? Were you able to easily set the mechanical advance? Were you able to limit the advance at a certain rpm using the included bushings? The $160 price won't seem that great if I have to also add on the cost of having it professionally tuned so I was wondering if anyone had success doing it themselves. I do own a timing light with the dial.