Looking to buy some drag radials for my 68 cuda fastback with stock location rear leaf springs, has 8.75 with BBP and 15x7 wheels with 4.25 BS they told me I could go as big as 275-60-15's? I would like to stay on the safe size and go with 225 to 265-60's or 50's X 15 let me know what you have. PM brand, size, condition and price with shipping to zipcode 81507 in Colorado.