shouldn`t my stall be helping my time on the strip?

As you are finding out, torque converters aren't an exact science. Escpecially if you don't have a dyno sheet to guide a choice.

The 10" 3500 converter I have barely goes that behind a 410" SB. Behind a 360 it might not get above 3000rpm. you might need a 9.5" or 10" converter to get what you want.