Few Questions,

Without knowing a bit more about the engine & assuming you have no problem buzzing the motor, I'd go to a 4:30 to 4:88 rear gear, launch at about 4500, shift somewhere around 62-6500 RPM making the motor actually pull. It sounds like you're just driving off the line and driving down the track.
BTW, mind if I ask where you got the car? It sure looks ALOT like one of my old ( and most favorite) ones.....