I put SRT headers and mid pipes on my 09 Challenger and you will need to buy an egr extension harness for 1 of the egr's. I also had to get another dip stick and tube from an SRT because the SRT headers got in the way. I had a place in Pa. do the install. It took 2 mechanics all day to complete it. They disconnected the motor mounts to get clearance required to bolt on the new headers. The SRT down pipes are 2 3/4" dia and the R/T has 2 1/2 " pipes. They will have to be adapted. You will have to get a Diablo Tuner to get the power out of the headers but from your butt you will feel the difference. I had to get a custom tune because the EGR's were throwing codes and it won't pass NY State Insp. so the car becomes a parked display only vehicle. Do keep your old exhaust parts in case you have to revert back to the old system. Rather than mess with the codes I bought a 2012 SRT. The fellow who bought my 09 the next day sold it within a year. Maybe now it is out of State. Tuned it did run like a bear, but not like my SRT.