You could put the pedal to the floor in neutral and see where it stops.

 

Not quite. Modern engines are limited when not in gear.

 

Exactly

 

Then use the paddle shifter to select a lower gear and try it out.

 

Yes.

http://www.wk2jeeps.com/2013/2013_wk2_specifications.pdf

ENGINE: 3.6-LITER DOHC V-6
Max. Engine Speed 6,400 rpm (electronically limited)

ENGINE: 5.7-LITER DOHC V-8
Max. Engine Speed 5,800 rpm (electronically-limited)

 

While in park and with warm engine I believe it is about 4K and 3k while cold.

Will Say that's a shame cause the the 200s awd would sound great at 5k+