Shocks won't set ride height but they can help bottoming out. A $24/pair shock is probably worse than anything you took out of an old bird. I have some of those cheap shocks like those in my truck. They are downright dangerous over a bump during a turn in the road. The back of the truck will leap out. Its a handful. Leaf spring rears and bad shocks can send you out of control.

I put Edlebrock IAS shocks in my Crown Victoria. It took the ride from bottoming out and uncontrolled rocking to well controlled but comfortable. The car was like riding a hobby horse before that change. Bilstens are the next level up. I didn't want a bone jarring ride for this car because my bones hurt. That is why I bought that body on frame car in the first place.

Shocks are very important to ride quality, including bottoming. The back of my 68 bird would bottom readily even when it was new. Decent shocks are much more expensive than $12 each. Bottoming out can be controlled by good shocks that resist that transient forces if the springs are appropriate. But if the springs are wrong, that needs to be fixed first. ?Ride height and deflection per hundred pounds will sort that out. Shocks won't fix ride height. They fix dynamic suspenstion action. Eaton knows this requirement, so you can trust their work. Give them a call if better shocks don't solve your concern.