If you're not running a box, you'll be fine. I've heard of people having good luck with the Innova timing light that you're looking at. Even when I add the box to a points ignition system it goes from being perfectly fine as a standard points setup but as soon as I switch the coil wires around and fire up the box it goes to a very bouncy timing mark that is difficult to time. I get the issue with any car here that I run the box on. It's not the MSD ready to run distributors or any of that stuff. It's actually caused by the MSD CDC boxes. If you've ever experienced it, it's the timing mark bouncing around. So is the problem inaccurate timing ,timing mark bounce,or something else? My old chrome sunpro with mechanical dial seems very steady.

035 end play when I took it out the other day. I measured my DUI ,which only had about 1000-1500 miles on it and it has. I measured it when I got it back and has exactly. I sent it back and they said they replaced the shaft. I did have to send the MSD dist back though cause out of the box there was zero shaft end play and it wouldnt spin freely with my fingers. This new MSD dist has a very stable timing mark at any RPM. Id rev up the motor with the DUI and the mark would move around some especially the higher the rev. Using my old gun on both dist I will say the MSD has the most stable timing mark in awhile. I took out a DUI 'tripower' small bodied HEI dist that I was having problems with(another thread) and replaced it with a MSD ready to run billet dist. I guess Ill just try it when I get it and see how it works. So thats why I asked here to see what your experiences were. Well while I was reading some q&a last night about whether this light would work with mSD ,I did see where there were a few that said it didnt work for them where the majority said it did.

Innova digital timing light