1/4 mile times
3 things you must do….
Tune it..… All of this is pointless if you have not tuned the car.
Get sub-frame connecters….. These are mandatory in any high power A-Body and will make even a /6 a better car.
Get a snubber…. A snubber is a very important part when running a stockish rear suspension.
Seriously…. You are putting the cart before the horse with your mods…. Fiberglass parts? Thinking about a gear change and fuel cell?
Get what you have, working first.
Sorry I'm so blunt….. But you know some of the things that are wrong yet you go after other things…..
It's like putting in a new radio because your doors won't lock…. Then asking why the radio swap didn't fix your door locks....