4500rpm launch...holy cow! What is that all about. I find it awfully hard to believe that you should need to go much above 2500rpm with some light feathering to get that thing rolling.

Is that a burning clutch I smell

 

Don't forget it takes a lot to get a truck that tips the scales at 5150 plus driver and fuel moving. Peak torque is at 4200 rpm so a 4500 launch should be ok depending how you ride the clutch out. I used to launch my Mustang at 5000 rpms dumping the clutch and got the best 60' times like that. It is going to take a little practice for these guys to figure out the best way to launch, shift, and drive these things. Plus it was the writer's first time out with it.