Tire Size for 5.5 small bolt rally wheels on 64 Valiant 200

Wanting to run 60s front and rear on 5.5 rally wheels. Not sure of the size but I have 75 series tires on the car now and they are really close to the front edge of the front fenders. Im thinking 60s will drop the side profile down and give me more room but the 225 size. Is that about the right width to go with? Thanks
Chas.