Every converter is a 'stall' converter, some have a higher stall speed than others. B&M rates their stall speeds for 230#ft of torque, so a 9:1 engine with less low end torque will not stall as high as a stock engine. I would use at least a 3000 stall converter, a good one from folks like Coan, Continental, etc.
If you want to win drag races, get some tires for that purpose. There is no substitute for good traction, and good traction will get you better traction.
With 9:1 compression and an XE268 you sure don't need race gas, you could probably run faster on 87 or 89 octane.