1964 Valiant Tallest Front 15" Tire

235 60 15s are too big. I'd rum 15 x 6 on the front, but have run 15 x 7 Rallyes also. I think 215 65 15 is the largest I have run on the front.
I'm trying to figure out how to run the same size all the way around....and 235 60 15 is as small as I'm willing to go on the rear. I guess I can just run the same height.