A little over a couple of decades ago I rebuilt the front suspension on my '69 GTO, and the things that really made it handle well was replacing the rubber bushings with urethane and some carrera shocks. Urethane on the swaybar will help, but putting them in the A-frames made a difference too. The biggest improvement I did was to get some really nice tires. That last addition made that goat stick like glue.

I used to be able to take this one certain set of curves at around 70 MPH, after the bushings and such I'd almost hit 80. It was handling much more solidly though, but the tires were still screaming and sliding. Eventually, I replaced the old Kelly Superchargers with a set of Eagle VRs and I went through them at about 95 MPH with no complaints from the tires. Damn things were $170 a pop back then, quite a chunk of change for a kid making $3.35 at McDonalds, but a change in rubber made an amazing difference.

I'm glad you said "controlled circumstances". A word of advice, know the roads you are driving. I was a stupid teenager when I was doing that, and I paid dearly. Unfortunately, I only had the new tires on my car for 8 hours before I wrecked it. Driving like a bat-out-of-hell flying through some s-curves on a road that just opened up. and I had never driven it before. It ended up dead ending into another road, no signs, no nothing. I figure I hit the curb head on doing at least 75. Luckily, I was fine, but the goat wasn't.

It's a blast having a car that will handle, just be careful.