Motor Trend tested a 303-RAV powered 1969 Trans Am, with a 3.90 gear, they (and Tom Goad, engineer) estimated 135 mph with the engine screaming at 6300 rpm. They believed the 303 would wind to 7000 rpm, and speculated a 150 mph top speed. But they didn't do it.

So a RAII or RAIII car, with a 3.08 gear, may be able to hit 140 mph. The limiting factor is their 5500 rpm redline. As we know, holding a Pontiac V8 at 5000 rpm for 10-15 seconds on a top speed run is asking for it. Pontiacs just weren't built to run high rpms for extended periods of time the way Chevy and Mopar engines were.

I stand corrected on the new Dodge Challenger. I was thinking of the "Top Gear" episode where they ran a mile (on the salt flats), and could only get the Challenger to 150 mph after some nifty duct taping of the front end to make it more aerodynamic.