Believe me its closer to 390 HP. Theres rear wheel horsepower dynos on stock R/Ts showing close to 400 HP. That is one reason they need to up the SRT-8s #s. It would be real hard to convince buyers to buy SRT-8 over R/T for 25 HP gain. So its best to under rate the R/Ts. Just look at what the 2009 5.7 Rams were rated at 390 HP. I still think there is room for more power stock. Exhaust manifold on 5.7 could use the shorties they use on the 6.1 to gain some as well as a bump in timing and a higher redline. Just to mention a few that a backyard mechanic would improve on.