I have 17in. TT IIs on my 68 Convertible. I will try and post some pictures. I will also check to see the backspacing I have. Can't remember off the top of my head. I did alot of research and measuring when I did this. I would recommend you build a gauge to measure the room you have in the rear to ensure you have the correct clearance. What I found when I did that is that I had almost 1/2 in more room on one side than the other, so you need to measure both sides. I have the info on building the guage, just requires a flat piece of aluminum stock, and threaded rod/nut. Pretty easy. The setup I am using would need to be special ordered because it is not a stock set up. The guy I bought from orders this configuration in quantity since he rebuilds many Gen 1s. It'll be tonight/tomorrow before I can get more info. Do you have an email address I can send the picts to incase I can't get them uploaded?