For drag racing, can I go with a smaller rim on the back with a bigger tire and keep my 19 on the front? - 1

Edit
2008 Ford Mustang

Right now im sitting at 245/45r19 fronts and rears 275/40r19

The reason for asking is because i cannot find a drag radial or Slick that fits my rim?

Read more: For drag racing, can I go with a smaller rim on the back with a bigger tire and keep my 19 on the front? - 1