Wheel and Tire width questions

I'm looking at putting the 17 x 9 steelies wheel vintiques makes on my 68 fastback. Wheels have a 4.5" back space. I was originally thinking 245/45 or 255/45 but then started thinking more and a 275/40 is the same height as a 245/45 and still falls in the 9 inch wide wheel width recommendation. Anyone know if the 275/40 will fit on the rear using the specified wheel width and backspace? Will it work on the front? I've got an old 245/45 tire laying around that I'm going to try using for a little measuring to see what I think but anything I can get from someone with experience would definitely be appreciated. Even someone saying they are running 255's and what clearance they do or do not have left is helpful.
[addsig]

if the 245x45's fit with no issues i would bet at least 265x40's would have no problems. i've found going to a lower series lets you increase the width due to less bulge on the sidewalls. with 4.5" backspacing do you have any clearance problem with rear springs?
I have a 69 ranchero, i would think it is the same specs as your 68 fairlane and im interested in your outcome.

[addsig]

http://www.woodyg.com/fairlane/finfo...alculator.html
copy this into your address bar, input your tire size and get dimensions

There are 6 1/4" from the leafs to the wheel mounting surface on the rear. There are 5.5" from the mounting surface to the "virgin" lip of the wheel well on the unrolled quarter panel. So, the 9 inch wheel with 4.5 back space isn't a problem although a little more backspace would probably be ideal. I'm going to go with those wheels and a 275 tire I think on the back. I shouldn't even have to cut the lip at all as the tire I'm looking at is a 10.9 section width measured on a 9.5 inch wheel. I might to something there anyway just for added clearance.

I had a 245/45 laying around so using it to do some measuring on the front it looks tight on the upper control arm at the 4.5 backspace. If I were to run the 17 x 9 on the front it'd be close. An 18 x 9 with that backspace would actually be great as the extra rim diameter would push things out past the control arm. So on the front I'm looking at either a 17 x 8 or a spacer on the 17 x 9.

I'll be sure to update when the tires and wheels are on for anyone else that might be interested.

_________________
1968 Ford Torino GT fastback - 289, auto, 2.79 rear
2004 Ford Lightning
Recently Sold - 1994 Thunderbird - DOHC 4.6L, 4.10's, big sway bars and lots of accompanying suspension mods.

<font size=-1>[ This Message was edited by: 4camtbird on 3/30/06 10:15am ]</font>