Will I reach 10,s??

What leaf springs are you running now? With a 4.30, I would think a 28" tall tire would be about optimum.

The spool will ET SLOWER than a sure grip with the same gears as the spool takes more power to turn than a sure grip...

I would experiment with an 11.20 car just the way it sits looking for that 10.99 before I would start changing something like gears/spool and tire size.

By experiment, I mean launch/shift RPM's, jets, squirters, timing, etc.

I added 2 degrees to our 416 stoker and went from 10.50 to 10.42. Then we ran the shifts out to 6,400 from 5,800 and went 10.33...and gained a full MPH to boot! Yea, a .17 gain from 2 little degrees and 600 more in the shifts.