Cheapest way to get an inch or 2...

Way back in my younger, stupider, and more broke days, I used some of these between the rear axle tubes and the frame on my '69 Dart.

View attachment helpersprings.jpg

They did raise the back for the look I was after and worked surprisingly well.
That was back then.
Today I'd save my pennies for new leaf springs so it's done the right way.

Another thing to remember, when you raise the back of your car you're also shifting the center-of-gravity forward.