Wheel well opening were designed around the tire and wheel combo.

27" tall tire is still 27" tall even if the rim is 15" or 18". What throws it off is the rubber to rim ratio, I expect to see more sidewall on older cars. I noticed on a couple of car build type shows they use a rim with a faux sidewall look.

http://www.deluxewheels.com/the-wheels/ as an example.

Which gives the benefit of a low profile tire with the look of traditional sidewalls.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.