Here's my take, and you've been around almost as long as I have: Until the early '90's, our old muscle cars were still ruling the streets. Even in stock form. New production domestics couldn't compare. Coming of age in the 70's, ten year old musclecars were not only affordable, but a lot more fun than the smogged out disco mobiles that were current at that time. Fast forward a bunch of years and our badass musclecars are still baddass---for what they are. Styling. Sound. Stance. Raw Emotion. Soul. But a new Camry will humble us. I like to drive my cars with spirit, but my days of replacing a blown up rear, trans, or engine on the weekend so I can get to work on Monday are over.
What has ALWAYS worked for myself and customers is to rebuild/restore these cars to close to stock condition, and then drive them like adults. It's cost effective, fun, and the car will behave on a drive to the coast or a formal night out to the opera. Factory parts= reliability. Aftermarket parts=issues.
What I've seen over the past 15 years or so with the new availability of aftermarket cranks, rods, heads, etc. is the misconception that that every street car has to have 500 HP or more to be worth anything at all. It's possible. A few gents here have just that. And these cars are rocket ships and a blast to drive. BUT---they are higher strung. More likely to be abused. More likely to break, and break PARTS. So---it's the 'end game' that determines the build. My slowest GTO happens to be my cruiser '67, with a stock detuned engine, carb, points, TH400 and retro-fitted 2.56 posi. But it's the one I drive most because it is the most drivable. 21 mpg on the road. Still no oil burning after almost 90,000 miles on my rebuild done in 1988 on a then-173,000 mile engine. Folks that are younger assume that a '60's or '70's car cannot be reliable and it will need an LS swap to be able to go to work and back. For anyone contemplating a build, I recommend some deep reflection on what the car will be used for and what your expectations are. When I built the 389 for my '65 in 1981, with the Sig Erson Hi Flo cam, etc. I had planned on racing the car on the strip. I ended up street racing the car and then using it as a daily driver for years and years. Now, 40+ years later, I wish it had a more mild cam to give it better low-end street manners. Tastes change as one ages. At 20 it was all about big cams, steep gears, and manual everything. Now, I want a mild cam, lazy gears, and power everything.
Rant over, just some of what I've seen and dealt with.