You can complain all you want about aftermarket speed equipment at this time, but in the 70s when they were still making the engines there was nothing but factory parts available overall.
You could buy an aluminum intake, headers, camshafts and that was about it. Luckily Pontiac factory parts were so well engineered, that the aftermarket parts sometime made less power than the factory parts, I.E. the aftermarket intake manifolds were lighter, but many times not as efficient as the factory ones.
I raced oval track cars in the 70s and 80s and we used way more factory engineered parts than aftermarket. I was successful using that formula.
At this time you can build a Stratostreak V8 without using a single factory part. For a brand that last sold it's last performance engine in 1979, I feel we have come a long way since the 70s. Don't complain too hard about aftermarket support for the Stratostreak engine when you haven't had almost zero support as we had in the 70s.
Larry Wenzler made the first aftermarket heads for the Stratostreak V8 with conventional valve arrangement, and when Edelbrock saw he was selling a fair quantity, plus being bugged by Arnie Beswick for years, they finally made some heads. then others started offering aluminum heads too.
Same with engine blocks, Dick Duclow (Indian Adventures) started making iron HP blocks, Kauffman followed.
The thing you have to keep in mind is that our sector is a tiny percentage of chevy lovers, so we have a much smaller pool of people and corporate entities to work with. It takes time to find people that want to invest in a really risky venture that has a small chance of money return. People have risked their life savings to bring some aftermarket parts to market, hoping they would at least break even.
I believe that some of the aftermarket will definitely go away in the not to distant future as we old diehards pass, but I surely wouldn't be complaining about what's currently available, the offerings now are 10 times better than in the 70s. We can't get new products without someone willing to invest the capital.............
I guess this reminds me of people that complain about the USA, they never leave it though. But some enthusiasts do defect, and put brand X between the frame rails of their cars, I call them quitters..........
The real pioneers of the Pontiac faithful made what wasn't mass produced for their engines, that's basically what hot rodding is about, not opening your checkbook and getting online to buy what you want. That's also how the aftermarket got started, someone makes a successful product that there is a demand for, and they start manufacturing it. If it's not available and you want it, simply get working on it.