6.2 hellcat crate motor

It has enough straight line power, I want them to start making it better in the twisties.
Even with so many ponys a GT-R, Z06 or 911 would eat it up in a road course.

That's what the Viper is for :D. Realistically the Challenger will never be as good of a platform for any kind of twisties. Frankly the Mustang and Camaro are in the same boat. You can only tweak and bandaid those cars so much to make them corner. In the long run you need a car that's ultimately built for the application. The Z28 gets huge praise for it's road course prowess, but look what it takes to get it there. Also, most tend to agree the tires are one of the largest parts of that equation. However, stacked up against a Z06 it gets whomped.

There's a balance with pretty much all cars. For instance, you typically give up a smoother ride for better cornering performance (this has gotten much better with adjustable suspension, but it's still there). The same applies with straight-line performance vs. twisties. A car good in corners will usually still do well in a straight line, but a car built specifically for straight-line performance will beat it as it doesn't compromise in other fields.

The gap is certainly closing as technology has developed, but I don't think it will ever really go away. We all want everything in one car, but a lot of times what a car isn't is just as important as what it is. The flaws are what make us appreciate them even more. A 700+ horsepower bruiser that sounds like valkyries descending on a battlefield is the image the car was designed for. It's not supposed to compete in the hypercar segment of 10 sec quarters with matching lap times.