Factory old iron just can't compete ... ??

Block strength. It's the only two words that jump out in my mind. Love them or hate them, ugly or not, the engines of recent muscle car years offer block strength. Our old iron blocks are at risk when pushing the HP close to 4 digits. Seems the new gen blocks of Ford, GM, or Mopar can handle HP well into the 4 digits. Big Boost, Big NOS systems, doesn't matter with new gen blocks. They make big HP. Street cars that can run 4 second 1/8 mile and 7 second 1/4 mile seem to be less rare these days. Who is competing with factory old iron?

4 digit HP is possible on old iron with turbos. A turbo that adds more pressure as the rpm goes up is easier on parts than a NA engine or a N02 hit.

As always, the ability to go fast is dictated by the thickness of your wallet.

The combo of a big engine in a light car is the first basic approach that should be taken. If a big engine is out of the question or you just want to do a small block (strokes or not) then the next expense is stable high RPM.