Hello guys and gals. This is Knan from Louisiana.I live almost on the coast of the gulf of mexico. It is in goose,duck and deer hunting territory. My occupation is pond crawfish farming. I have not heard of many roadrunners south of I-10 between Texas and Miss. I have owned my 69 R.R. for about a year now.It has a 383 cu. engine,holley 750cfm. carb. headers,aluminum radiator,14" factory wheels. this is the way I bought it. I,m ready to upgrade wheels and tires.Plans are weld draglite 15"x6" front on 225/70/15" B/F. Rear will be 8"-9" with 4.5 backspace,0mm. offset on 275/60/15" tires.Summit did not list offset on 9"x4.5 back space rims,Oops I grew up calling these rims instead of wheels.I am open to any suggestions? Nice talking with you and I am glad there are people like you who understand these 69 Roadrunners Thank-You