Just saw this post. Better late than never? I stuffed a 295/50 R15 under 2 of my stock 87 TTypes with the stock rims. The brand was a cheapy Futura Brand sold by Pep Boys and made by Cooper tire. They fit just fine and only rubbed if there were people in the back seat or if I cornered hard. Other than that they fit fine and looked good.
I got the idea from a friend named Ray and his Blue 87 T aka the "Blue Monster"
HTH