New to this forum, or any forum, I hope this is the place to pose this question. I have read and understand the importance to maintain the height (or circumference) ratio of front tires to back tires. The problem is I don't know what that ratio is for my newly aquired 1720. The Ford has turf tires and the fronts are in need of changing can I go to R4 in front if they are near the height of the new, original tires I am replacing? Too cheap to replace the rears since they have tread left but don't want to damage anything. Thanks.