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
thanks for the input - had done it for many years on my bbp 14's.... wasn't sure about the spb being slightly narrower.... Now as long as the fit under the rear of Jake's 65 B'cuda, we'll be good......