At 189 mph was the GTO 6.0 the fastest Pontiac ever made?

Especially to compete with the Ford GT, Dodge Viper and other American sports cars/grand tourers?

From my archived, now-deleted question:
The modern Pontiac GTO was a luxury grand tourer rather than a true "muscle car" like the GTO of the 1960s and '70s. The 400 hp 6.0 LS2 version is my favorite. 40,745 'Goats were produced between 2004 and 2006 (including the 350 hp 5.7 LS6, both of which were based on the Chevy Corvettes - C6 and C5 respectively). GM only built 27,994 Chevrolet Corvette C6 Z06 cars. Stock (including its BFGoodrich g-Force T/A KDWS, 245/45ZR-17 95W M+S tires) it could do a Car and Driver-tested 0-60 sprint in 4.7 seconds and quarter-mile sprint in 13.3 seconds. Top speed is 155 mph with the limiter and 189 without it (<<< oh yes, I've done that at Volkswagen's Ehra-Lessien track in my 2005 back in January '06 when the 'Goat was still in production - no kidding!). It has a 0.31 drag coefficient and 23.7 square foot frontal area, equating to a 7.3 square foot drag area.

Added (1). It was Pontiac's version of the base Corvette. It was 4 mph faster than that Corvette!

Added (2). By the way, I was talking about production Pontiacs, not racing Pontiacs like the Promod.

Rodney Butler & Travis Quillen's 1963 Tempest Promod 6.27 @ 228 MPH but that is about as much as a Pontiac as your badge engineered Holden Monaro. The Viper and the GT would both blow the doors off your GTO with the Viper speed limiter set at 180 and the GT at 205 both are just in a different class all together. I apologize for sounding quite harsh but for some odd reason I have a huge dislike for the 2004-2006 GTOs. But I'm fine, to a point, with rest of the Pontiac line.

Nope! It wasn't the fastest sorry

At 189 mph the GTO was the same speed at anything else at 189 mph. But a GTO would never run that fast unless it was off a cliff or some serious downhill. Not even one with a Chevy motor. Sorry, it will not. Never.