Yes 30 crank deg from the plate is going to b way too much. I'm thinking you do not want to mess w brazing the slots shorter so I'd get the plate from FBO (should b cheap) that lets you limit the adv & want 8.5 in the dist (17 at crank) along w your 18 initial. I think if your idle sp is below where the curve starts you will b good and I'd actually snip 1 coil off of 1 end of each of the OE springs (snip 1 end only of each spring) which'd slightly raise the kick in point then w your needlenose pliers bend a new loop out like it was. You've gotta alot of info coming at ya , holler how it turns out & what the solution ends up being