I was looking for some input or advice on tire size. I have a 74 cutlass that I have upgraded from the 14' rim to the 15x7. I am thinking of 245/60/15 all the way around or possibly 255's on back? I don't mind a little rub in the front if it's when the wheel is turned the whole way in one direction, I just don't the outer fender to scrub tire while driving. Thanks for your thoughts.

 

Try the search function above. There is a lot of threads on tire size. 245's should be fine on the front and rear. I run 275's on the rear with 255's in the front. Some run even wider on the rear than mine with 3" exhaust. All depends on preference and back spacing on your wheels. With the 255's in the front, they clear fine with stock height springs in my 72. May be different in 74.

 

I'm a big fan of 245-60s. I just upgraded to 15" SSIIIs and have 245-60s all around.

Back in the 80s I had a variety of tire combinations on 15x7 alloy wheels:
225-70s all around
235-60s up front and 255-60s in back
245-60s all around

I liked the 245-60s all around as they were wider for traction and lower sidewalls for handling and I could rotate the tires, which I couldn't do with the 235 front/255 rear setup.