Absolutely agree 100%......I think it is possible to have bad luck and just over the line on a lot of deductions and not have the full effect of any? Of course this is just for conversation sake ...
and I see this with your car... 4.10's just gets you to -.7, 28" tire not quite reaching the 29" needed to +.2, subtracting .4 for the overbore, but somebody will be .060 over with 10.1 compression, yeah, you might be the best example of your statement. I still think low 13's are in reach with your build, I really do, and that will get you close. Glad your playing, and you have got me glued to your build (regardless of this race), you are going right up my alley ....
I still think the box should get most within the ball park, and still should be a lot of fun. AND HEY, It's FREE..........