60's on a smallbolt rallye wheel?

My Dad has been running 15x5.5 Rallye Wheels with 235-60s up front and 275-60 out back on his Charger for the last 20 plus years with no problems at all
No uneven wear or anything
When I got my 73 340 Duster with its factory Rallye Wheels on it it had 245-60-14s out back and 195-60-14 up front