I have a pair of oval track springs for my dart. They are .5" longer in front (20.5"). I know there are shorter hangers to properly locate the axle. But I was wondering - can I just run the old hangers with the axle 1/2" rearward without issues?

It may cause drivshaft issues. 1/2" change to the shaft location could cause it to be to short and create vibrations and excess wear to the rear trans bushing and tail shaft. Driveshaft length is critical to less then an 1".

You probably can. Or, you could elongate the locating holes and move the axle up on the springs.

R.

As stated above, I don't like to pull the front yoke out of the trans any more than necessary. But sometimes more clearance is needed at the front of the tires. The other thing for me is how the wheel & tire look in the opening. If the rear hanger isn't hitting the frame rails, you could relocate the centering pin forward, or depending on the setup, relocate the front spring eye forward. Either way, check yoke spline engagement.

Thanks for all the input. I'm getting the front hangers to have it positioned correctly.

You should have room to drill new holes on either side in the front shackle to locate the horizontal bolt further forward & the limit would likely be the distance between the front eye & the rear side of the front face of the front shackle. If you have the distance available & if you have to drill the holes center to center further forward than the .5" you need just to clear the current hole(s) then you can space the shackle rearward from the frame that extra distance. Keep tabs on the driveshaft end play & the angle of the rear shackles

To run a big tire on a Dart, I do recall the front edge becoming a problem.

If you are running a big tire, check it out before you modify your front hangers.

Driveshaft and rear shackle needs to be address too.

A friend of mine talked about having put some "adjusters" between the rear axle spring perches and springs that can be adjusted with a wrench or socket to move the axle front or rear to correct the wheel alignment. I can't recall the name of them, but it might help you out in this case. It may allow you to not only set the rear as close as you need, but also custom fit for tire clearance if the driveshaft is long enough. Anybody out there familiar with these?