wheel size and backspace

[RoadRod]

I have a 72 chevelle ss that I would like to put 20 by 11 in wheels on the back and 19 x 9 in wheels on the front and I need to know what backspacing and what's the largest tire I can use, I will cut or roll fenders but do not want to tub, any help would be appreciated, thanks

[First Bird]

There are a lot of good answers to your question in the Sticky at the top of the Wheels & Tires section. Also, answers to your question can be found in the forum if you search with words like "Chevelle" "backspacing" and "wheel".