Shift axle over to fit wider tire?

Wanting wider rear tires. 255 now, want 275. Problem is the passenger quarter panel lip is too far in by 1/4”. That panel was replaced. I figure I only need another 1/4” - to be safe - so the lip won’t rub the tire. Lip was already trimmed to the welds. Not enough left to roll it. Plenty of room on the driver side. Not wanting to change the wheels. Not wanting to reposition / re-weld the spring perches.

So my question is how much might be gained by loosening the leaf spring U-bolts and shackles on both sides, wiggling and prying the axle toward the driver side, repositioning the U-bolts and tightening it all back?

Besides this, open to any other creative ideas! Thanks a lot.

Might want out bust out a tape measure and see if the axle is square in the chassis. The FSM will give you the spits to measure against. Might find you are out of square as is, or will make it out of square shifting it and then you dog track.

Take the rear shackles off, get new rubber bushings for them, loosen the u bolts then push on the shackle end of the springs & measure the side to side room, tighten u bolts, reinstall shackles but DO not over tighten them like most people do, I did this but I have sliders in place of my Shackles worked great.

/\ excellent answer.

If the front fender was rubbing on one tire, would you run a negative camber to clear it?

end of thread.

LOL, like these cars were square when new LOL, moving the rear over 1/4 of an inch will not cause a problem & yes I said to measure things I used the inner wheel well to measure off of

My car has all the OE sheet metal and was still off. I cut the spring perches off, slid them over 3/8", and rewelded. Doesn't change the way the car drives at all. My Challenger has been like this 17 years.
Doug

I am the original owner of a '74 Challenger. When I took it for it's first front end alignment, the shop found that there was a one inch difference in wheelbase from side to side. I took it back to the dealer and complained until they fixed it. IIRC they cut the perches off of the rear axle and welded on new ones.

and yet a "trick"[?] for drag racing is to get one wheel ahead of the other by 1".

I do believe the 1" stagger refers to the front end. You don't want the rear end steering the car.

yes, the front end. never the rear !

There were advantages of having the rear end steer the car a bit on the old dirt track racer...

If I remember correctly, the allowable body tolerance on the late 60s Mopars was + ? - 1/4". That could easily add up to 1/2" difference. Don't really remember many where the rear axle was actually centered in the wheel wells, most had one side wider the the other side.

Not all cars were as crooked as you guys think. I measured my 69 Bee's rear axle with plumb bobs. To check the thrust angle to the center of the front suspension. I was within a 1/16". This is less than a 1/16" over 117".

So what if you are correct and it is off 1/4". Then you want to move it over another 1/4". That is now 1/2". Unacceptable. Try a little harder to get things correct and stop accepting the fact that these cars had poor tolerances.

I can understand not wanting to unweld and reweld a car together to make it a little better but do not reweld to make it worse. If the problem is in the body/quarter. Adjust the quarter. It would not take much to pull an outer quarter over a bit.
Square cars for the road, this is not dirt racing or moving a wheel ahead to catch a win light.

I have nothing to do with this project, I only added a short comment about the dirt track days, and factory tolerances.

I've seen some really messed up original stuff through the years, but I've seen some nearly perfect original stuff as well.

When I welded stuff together, I worked really hard to get things as even, side to side as possible.

That is unless it was the dirt car. With those, having the "right" poor body tolerance was usually a good thing. "Factory stock" by the rules, poor tolerance in our favor. Gene