Ill pull the wheels off later this evening and get a measurement out to you. Those wheels look good. What are your thoughts about 5.5 backspacing for the front, seems a wider variety to choose from at that backspacing? the 245/45/17 tire sounds about right. thanks for your help
5.5” of backspace for the front is fine, that should work great. With a 17” rim the backspace limit is usually around 5.6”-5.7”, right around there is when the outer tie rod end starts to become a clearance problem. It does depend a bit on the style of the rim, but if you stay under 5.6” on the backspace with a 17” rim it should clear fine.
With 18’s the outer tie rod actually fits inside the lip of the wheel, which is why 18’s allow even wider front tires (275’s!). But for 245’s or 255’s 17’s work great.
Kind of doing it in reverse order. You need to make your mods first. Obviously you will not be using the stock brakes front or rear so the bolt pattern is moot. It will now be the standard pattern. 5 on 4 1/2. so wheels selection will be unlimited. Cragar S/S is not a performance wheel. Maybe in the sixties/seventies but that was before radial tires and ultra low profile tire were made. The suspension is a combination of the control arms, shocks, tires, wheels etc... You need to plan out the total combination from the start.
Like buying a cam and not knowing what induction, exhaust gearing, weight etc...you are building for.
Actually I disagree wholeheartedly.
I always start from the tires I want to run. They decide
everything else.
For example, if you’re building a car for handling and you decide you want to run 275mm wide tires up front with a 200 treadwear rating, that sets the wheels and suspension. You need 18” rims to do that, for example. Then you’ll have a ton of grip, so you’ll need larger diameter torsion bars. To get the alignment right for large torsion bars and wide modern tires you need tubular upper control arms. With that level of grip you’ll need a sway bar, chassis stiffening, etc.
On the flip side, if you want 225/60/15’s up front on a stock looking wheel, you can run pretty much all factory components with a few minor tweaks (offset UCA bushings, for example). You can benefit from larger torsion bars than stock because all of these cars can, but you don’t have to go crazy because you’ll be tire limited.
So if you’ve already set your suspension before you’ve picked your wheels and tires, you may have set yourself up for failure. Or at least locked yourself into a path already. If you rebuild all the stock components and throw a set of 18’s with 275’s on there you’ll be buying all new suspension again when you realize stuff hits, the alignment is wrong and the body roll is ridiculous because you done have the wheel rate to control that amount of grip. If you build some high dollar suspension and toss 225/60/15’s on there you’ll have wasted a ton of money, because you don’t have the grip to put any of that stuff to work and you’ll just slide around before the suspension gets going.
Sure, you have to know what some of your suspension will be to get the wheel offset right, but realistically the brake kit usually sets most of the track width. And the tire width determines where the tire has to sit, so you have to know that already too. And your brakes may be tied to the wheel diameter too! In my case, my wheels, tires and brakes all had to happen at the same time. My 13” brakes won’t take a 15” rim, and my 275/35/18’s and 18x9’s won’t fit the stock disks without a spacer because they have extra backspace for the additional track added by the 13” brakes. And because of that backspace they need a tubular UCA to clear the control arm at steering lock. So all of that happened at the exact same time. But I knew what I needed because I knew what tires I wanted first, and everything else fell in behind that. With a less extreme set up you can get away with some things, but really everything in the suspension and chassis starts from how much grip your tires have.
