Jason - if you read this , or anyone else. I have a 31x10.5Wx15 ET Drag slick mounted on a 15x10 weld wheel. I have measured the section, tread & height. Can you tell me what will change if I go to a 15x12 wheel. This is on a 66 nova. The wheel I have now is a 15x10 with 4.5 BS & I am thinking of going with a 15X12 with 5.5 BS , adding a inch to each side. What should my numbers be for clearance. Thanks for the help.