slant timing with turbo

How would i change the all in timing? is that limiter plate a good idea? i dont want to drop my inital timing down to where my total is 25?
I like the limiter plate idea. I have one on the electronic distributor in Vixen now and one in the points distributor that came out. Word of caution though. The actual timing you "end up" with is different than what the slots are marked for. On both of mine, the slots did not limit the total timing "as much" as they were marked. I don't know it that was because of it being a slant 6 distributor or not. I don't believe it is, because I've seen others on here with different application also say their plate did not match up with what the slots were marked for. I forget what the "least" advance slot is besides zero, but that's where mine is and it's limited to 10 degrees mechanical advance. So I run "around" 20 initial. But keep in mind, mine is also N/A.