We need the red X back
I actually put more into my last /6 because of all the V8 conversion parts I didn't have to buy and didn't have on hand.... Trans, motor mounts, exhaust and more.... I haven't had a "fast" car yet and at this point in life probably won't....
But I improved my/6 quite a bit over what it was originally... enough to notice for sure.
Would I want one for everything? No. I wouldn't want to try and pull my 28' camper with one, but for the daily grind back n forth to work it'll do the job just fine.