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.
Yet I did at least a dozen 140+ mph runs with no damage - after upgrading the fuel delivery. I ended up putting that engine (about 380 hp) in a Street Stock oval track car that hammered the Chev and Mopar engines that were running the same class; two seasons with no failures despite the stock rods.
No, the Pontiacs didn't rev as freely as some other engines of the time but they certainly made good power and more than held their own on the street. I once had a long run against a '68 GTX with a 440 4 speed and rather enjoyed toying with him when he ran out of revs at about 125 mph. I made a point of backing off and running up on him several times as he could only maintain his speed for fear of blowing his engine. All he could do is glare at me.
I find myself imagining how much fun I'd have in my '69 with 200 lbs less weight on the front tires and another 140 hp - just dynoed an all aluminum L92 engine (long block weighs 380 lbs) from a 2008 Escalade with a very pretty aftermarket IR EFI intake system, mild cam and headers that made 450+ ft.lbs of torque from 3000 rpm up and 520hp at 6000 rpm. Stopped at 6000 because of the stock rod bolts; adding ARPs would add another safe 500 rpm, high enough to find the real hp peak. Idles with a nice burble at 750rpm.
That was a customer's but I have my own all aluminum 6.0 with 243 heads waiting for a new abode. This is the same basic engine that we run in the NASCAR Canadian Tire Series with the addition of forged crank, rods and pistons that run to 8000 rpm regularly with hydraulic lifters! Crazy how stock these engines are and make 500+ hp with a 390 cfm carb. They make 550-560 streetable hp with a bigger carb.
