Ever been a hair from a lower second and cant get it ?

Do you run an accessory belt? If so, you might pick up a little if you remove it before the run.

What about chassis stuff? Have you tried adjusting tire pressure up or down? Adjustable shocks? Do you have a video of your launch to see how the car comes off the line?

Maybe with all the recent mods your optimum shift points may have changed?

What converter is in it? Perhaps you need it to be adjusted with the changes?