I figured that I would be replacing most everything. Replacing with what is the question…?
The stiffer you make the car body mounts, control arms, frame. The flex has to go somewhere. Poly mounts still have some( though more limited) flex. The next weakest part gives. Also you have to look at the defection of rearend, control arms, shocks,and weight distribution(gears and tires never forget tires!)
If you want handling and straight line you fight one over the other. You have to pick one to be more over the other.
If straight line is your choice but driving regularly you can add drop mounts to the bottom control arms to help rearend twisting and weight distribution. Or ladder bars and add almost none and increased weight transfer from further forward lifting the nose weight to the rear for traction. This leaves 4 weak points,drive shaft, u-joints, ring/pinion, and axles.
Many of the people on here building for drag racing will tell you there’s calculations to figure it out.
60’ times equal all this and end with the idea of 1/8 mile or 1/4 mile times.
Hopefully this sorts some stuff out. But on line you have to give all the information then see if the people with a lot more knowledge than me have your answer.
Also there are a number of threads here you can fallow to help you.
And something you can think about and have fun doing is go to grudge nights at the track. Then you can point and ask questions get pictures 😏😎