Hi everybody
Please help.
I have seen that the most common backspacing for 70-72 chevelles(on these pages)is 5,5"inch.Will 10x15" wheels with 5" backspacing and 275/50 tires fit.

In advance - THANK YOU.

We have chevelles overseas? I did not know that. A topic a few down has the answer, 5.5 may rub.

You should be fine for that size street tire.
With slicks you might get in too deep on the frame and hit.
A 295-50-15 will get you in trouble so don't go any larger... than the 275..