Appropriate Wheel Offset for 18" Wheels?

72bluNblu said

I don't think a 265 will fit with the stock spring location either. When I mounted the 275's on my Dart for mock up, they were physically in contact with both the quarter lip and the springs at the same time, to the point that the wheel was obviously dragging on both sides when rotated. 5mm of space per side isn't going to cut it for clearance, and I don't think you'll be able to get enough out of cutting the quarter lip to make them work on the road.

A 275 really needs that 1/2" offset, and even then, its still pretty much maxed out with the quarter lip trimmed back. With the stock spring location, I think a 255 is as much as you can safely run. And depending on the tire, car, and spacing, even the 255 might take some trimming.

Click to expand...

I'm curious now... Because I know there are quite a few cars with a 275 series tires and I never here them mention needing offset shackles. I've got to do some research. I autocrossed with Tomswheels and his '67 Valiant and he was running 265/35/18's all the way around (granted he had an 8.8 in it). What about the Red Valiant or the Green Brick? Anybody know about those?

What needs to be modified for the 1/2" shackles because the idea of how they work isn't really connecting in my head. I'm assuming the perches need to be moved in and the offset shackles move them on the frame side, correct? If not, it makes more sense to pay $150 for the kit instead of $250 on tires (just back two). If so, I'll just do a mini-tub years down the line and move the perches then.

Also, the car needs to be on all 4 wheels within the next 2-3 weeks or so (before school starts hence the rush).