The dyno shop needs to have a STAR Diagnotic tool to put the SRT6 into dyno mode, (your BAS/ESP light will be illuminated during the runs) then you can dyno up to your preset RPM limiter with the front wheels stationary.

Some of the more modern Dynos have a build in DRBII cable to plug into the diagnostic port to monitor the cars sensor (IE a Dyno-Dynamics) and can also put the car into the dyno mode - This is what Speedinnovations had when they dyno-tuned my SRT - the stock or baseline pass only revved to 5800 RPM - once SI set the Rev Limiter to 6250 RPM's - thats where the rest of the passes were dyno'ed to....