No it it's probably about the same as buying the SRT, but not many SRTs will turn 12.19 stock. None that I know of. A few mods on the SRT will get you there though in SOME cases, Diablo tune, short drag radials, etc. From there on out there is little difference mod for mod between the R/T & SRT.
Cam, heads, headers & tuner on an R/T = 100-150 RWHP gain.
Same mods on an SRT = 50-75 RWHP gain.
Besides, anyone can go out & "BUY" an SRT. It's a lot more fun to have a "sleeper" R/T that will kick some A$$.
