[ted]

That was awful lengthy. To my point, those dial adjust timing lights don't always read accurate. This is due to the various electronics in them and that knob that is supposedly scaled correctly to that decal. Even my dyno shop is aware of this and instead of using the shop's dial-adjust timing light, recommends to their customers that they bring with them a conventional timing light. I've solved customers problems with their engines by finding that their timing lights were automatically putting more timing into their engines than what they thought they had.

I haven't looked at an MSD instruction sheet lately, but they use to specify what kind of timing light to use and those "total" reading lights were not on the list. If you're using an MSD box, then you also need to back up the timing at least an additional 2° to compensate for the extra burn time in the spark.

One suitable procedure for total timing is to rev the engine until all the timing is in (mark has quit moving) and read the total amount of timing either on the damper or timing tag (depends what motor you're working on). For all my race engines, I recurve the distributors so that all the timing is in by 3000 rpm. This works well for my foot brake car that I launch at 3200 rpm. A timing tape works well on the damper providing it's for the correct diameter. It's also easy enough to put the appropriate marks on the damper when it's off and just use the "0" on the timing pointer.

If you're still intent on using that timing light, then check your total timing again using a timing light recommended by MSD or some form of conventional light. I haven't seen an issue with inductive timing lights versus those that just hook up in parallel.

I hope this helps.