What,s a good RPM to launch a 4 speed?

I would say use your line lock and load the diff by letting out the clutch a hair, wind it up and let it loose. Most breaks using a 4spd is caused by not preloading the drivetrain. This is a must to reduce the chances of something going boooommmmmm. Just a suggestion
well thay always told me if your afraid of brakeing it don't race it. becuse with a 4speed its going to brake.and if the cam is makeing power at 5800 i would bring her off at 6200 by the time your off the clutch youl be in the power range.then be man about it put the nee lock on the right leg and shift it like you mean it....MOPAR TO YA!!