What gear ratio for a street car w/occasional track use?

Stock flywheel, I would not trust that.

I would spend money on a quality SFI one before gears.

That occured to me as well ...

I am using a 20 lb Mcleod SFI flywheel for my stroker... a little less weight (10 lbs) for quick revving and peace of mind for around 299.00

with all the trick driveline stuff you have it seems ashame to run a factory iron unit.