Ive got a 72 dart swinger (/6, so small rear end and bolt pattern). I want to fill out the rear end and give it a bit of rake. What is the tallest and widest tire i can have back there under the stock suspension? Moving up to 15" rims, whats offset will i need? And being hopeful; but if i get 15" steelies, will i still be able to use my dog dishes on my 14s?