I had a thread going last week that died. I have a 69 conv. I am going with a set of 17" wheels all the way around. I also have drum brakes. I would like the widest tire possible. I am also contemplating a 1.5"-2" lowering kit, it has the original rubber bushings and since I'm tearing into it I just though it might be the "pro-tour" thing to do. If I do lower it I'm worried about tire height as well. I want the tallest tire to boot. As far as backspacing I think 4.5 will do it all the way around, although I have seen in the mags 5.5 in the back with 275's. I do not want to bend/roll my fenders to allow a proper fit. I have heard mixed reports on that issue with 275's. The Nitto 275/50-17 looks to be a shade over 27" tall, but will it fit lowered? I need heeellllpppp pleaaaaaase!!!! I'm sorry if I might be beating a dead horse but it seems like everyone has a little different perspective on this.

4.5 BS in the front should be fine. Most guys run a 275/45 or 40 on a 9.5 inch rim on a lowered 1st gen in the rear. I think a 50 series tire would be too close unless you want an 8" rim with a 255. Some roll the lip and some don't just depends on the alignment of your rear end. For a rear rim that wide (9.5")you will have to run 5.5 BS in the rear. Also, you may rub a little on hard corners, just depends on what you use the car for. I have a 67 lowered 2" and went through this same thing so I went to my tire guy and he loaned me a TT II to take home and try out. I fully recommend this before the purchase because once you order the wheels with that kind of backspace, they are yours. Hope this helps.