FBO plate over advancing

Well, I just installed and FBO plate in my dizzy with the intent to limit it to 10* of mechanical advance on my 340/416. I went with one light spring and one medium, based on threads I searched here.
It's bedtime now but I'll fire it up tomorrow and set/check the timing curve & play with the vacuum advance and report back with results asap. I may still end up going the old tried & true weld method before all is said and done. The FBO "seemed" like an easy way to try different curves. Now I'm a little skeptical. LOL
-still learnin'.
G'night!