1967 HiPo 289 questions

Hi. My name is Rick and I am working on developing a totally accurate model of a '67 HiPo Mustang for a die cast manufacturer, (sorry, can't say who right now). I have a couple of questions concerning exhaust and tires for which I have received conflicting information. I have posted my questions on the "Restoration" forum and I am hoping to hear from anyone who can give me the straight answers. I figure this is the place to find out...thanks in advance!