Coker makes a 600x16 radial with the same diameter and cross section as the bias ply but they are EXPENSIVE. A 185/85r16 is a close match but no one sells that size in the US that I've been able to find. Diamond Back sells a 195/80r16 that has the right diameter but is wider and could cause clearance issues in some cases.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.