[F-BIRD'88]

Get some tires that have traction. If a 23" is as tall as will fit, make sure its a sticky drag radial.
EG: P225-50-15 BFG drag radial. A normal street radial tire is all but useless at the track. They are made for long life not straight line traction.

A 8.5x 26x 15" M/T ET street Bias ply tire which is effective 25.5" tall will make a huge difference.
Its real hard to get a good track ET with a crap tire, reguardless of the gear ratio.

You will know you got it right when the front wheels go airborne on launch.
You got to get the weight back on the back tires to get a small tire to hook up. Weight transfer. But you do not want the rear suspension to squat on launch.

You can rev that engine a lot higher than 5500 rpm without fear of hurting it.
if thats is your self imposed rev limit port the camel backs and reinstall.
The 600VS carb is not doing it any favours. What is the exhaust system like?
Its all about total system air flow. Heads are only one component of the air flow chain.