Nah, the SRT6 won't out accelerate a GTO (05 or 06) with the LS2 engine. I owned an 05 GTO for three years and I've owned an SRT6 for about 8 months. The GTO is ~600 lbs heavier than a Crossfire but has considerably higher HP (400) and torque (400) peaks as well as a lower rear end gear (3.46). The stock GTO was a 4.8 sec 0-60 car and so is the stock SRT6. Also, both engines have similar broad flat torque curves and both pretty much run out of steam around 5,800 RPM. The GM 4L65E automatic in the GTO is a good match for the GTO if not as sophisticated as the box in the SRT6. The Tremec T56 6 speed manual on the other hand was a piece of crap. I know, that's what was in my car.

The GTO and Crossfire share other traits as well. Both got no love from consumers. And both were very short production runs at small quantities. They were both hand me downs from the 90's too. The SRT6 came from the late 90's Mercedes R170 platform and was massaged by Chrysler. While the GTO came from another mid 90's German chassis this time from Opel, and was built by Holden in Australia with tweaks specified by Pontiac. The SRT6 borrowed an engine from AMG. The GTO borrowed an engine from the Corvette. If these cars aren't genetically related, they are at least spiritual second cousins.