Sounds like times for a 300 SRT8. Is that what they gave you to drive?
Chrysler 300 0-60 Times - Updated 2022 - 0-60 Specs
The SRT8 with the 6.1 looked to run 13.2-13.4 @ 104-109 depending on who was testing it. The 6.4 version ran a 12.9 in the above lists, though, at 110+ mph.
For comparison sake, the 6.1 and 6.4 really should be the level compared to the 340. The 5.7 is a truck motor, and even makes less hp in the cars than in the trucks after ‘08. The 340 was a performance motor from the start and should be compared to a performance motor like the 6.1 and 6.4, not to a pedestrian version like the 5.7.
Funny thing is, the pedestrian pre-Eagle 5.7 still runs with a stock 340
despite the weight advantage a 340 Duster would have. And the ‘09+ 5.7 is like 5 tenth quicker than the early 5.7.