Launch RPM for a 4 Speed?

[CopoFan]

So I finally got Ribbon COPO out to the strip this past weekend (first time I've ever drove a stick down the strip), and was disappointed with 4 passes all around 13.70. I was running slicks, and it has a pretty nasty bog when launching, even with the RPM's up in the mid 3000's. Tires didn't break loose at all.

I know we jetted the secondaries up at one point, and at that throttle position, the secondary accelerator pump is probably out of the picture. Timing is around 17, almost 40 at 3500 RPM. It runs fine on the street.

Its got a built 396 (11.5:1), 4 speed and 4.10 rear. My buddy did have a high 12 pass with it, and he didn't shift it too well.

I assume it just needs more RPM's at the line... but how high is safe? I'm not looking to break anything. I'd hate to damage its KQ rear.

Also, any chance of hurting anything since it has ladder bars, or do those actually help?

Thanks!