Shift improver kits

I agree with all of the guys above. I have been using the B&M kit for over 40 years now.
Still remember installing my first in a 69 R/T back in 1976.My last is in my car now year 2022.
Easy to install.I remove the valve body and work on the bench.
It gives you a good 1-2 shift that can bark the tires IF that is what you want.
The kit has 2 settings one a bit softer,depending on your needs.
Tho there are other brands out there B&M is my brand.