Can I run 245/45/17 and 275/45/17 on a 1969 mustang with altered suspension

[6969stangg]

Okayy so I know this is a topic that has been talked about and I have been searching through endless threads trying to find the answer so please help a new guy out. I just got a 1969 coupe and I’m completely rebuilding the front suspension and swapping the drums for wilwood discs brakes. I’m going to be using global west upper control arms and Hotchkis lowering springs, along with doing the infamous Shelby drop. Now it’s my understanding that the Shelby drop should lower the car about 5/8 inch and the springs should drop it 1/2 inch. With those mods will I be able to run a 245/45R17x8 with a 4.5 backspacing?? Now the rear suspension is stock, will I be able to run 275/45R17x9 5.5 backspacing on the back without doing any mods or fender rolling? Is anyone doing this or is there a possible better wheel tire combo?? Should I just stick with 17x8s on the back? It’s a lot of money to gamble with so thanks in advance