Rear Sway Bar Question - Using a 73 mount on a 72

[plymouthman72]

My 72 roadrunner rear sway bar bracket has bit the dust and I am on the hunt for a replacement set or just the drivers side since my passenger side is good. I have located a set for a 73-74 and its very similar with the exception of the the larger hole for the isolator set up i the 73/4 cars. Is this a direct replacement for my car and can I put it in even if it has the larger hole? I am not a numbers dude, I just want a functional rear sway bar. Here are some pics of mine and what I am looking to buy. I appreciate all the help!

Mine:

For Sale:

 

[72RoadrunnerGTX]

Should be able to weld in a washer or plug, replicate the correct size locating hole for your pre-’73 application.

 

[plymouthman72]

This may be a dumb question but why couldn't I just leave the bigger hole?

 

[72RoadrunnerGTX]

I personally would not depend on only the U-bolts passing through the plate for locating, plate could shift out of place under certain conditions. Short of welding, I would at least, fit a washer with correct inner and outer sizing in the bigger hole. Make sure it is not thicker that the plate.

 

[plymouthman72]

I personally would not depend on only the U-bolts passing through the plate for locating, plate could shift out of place under certain conditions. Short of welding, I would at least, fit a washer with correct inner and outer sizing in the bigger hole. Make sure it is not thicker that the plate.

That makes perfect sense! I was thinking of trying to fabricate a piece for my rusty one since it is only a section that is missing but this seems like a much more reasonable solution. I didn't know these were so hard to find!

 

[PurpleBeeper]

If I'm seeing this right & the "hole" your talking about would go over the leaf spring locater pin..... then yes, you DEFINITELY need the small hole, however you get there. Welding up a washer there or a piece of plate steel & drill your own hole would work too. OR weld back together your old lower spring mounts. Regardless....you NEED that hole to be really close in size to the leaf spring locater pin or your car will eventually "crab" & the rear end will be pointing a different direction than your front wheels making the car drive sideways down the road.

 

[72RoadrunnerGTX]

This sway bar plate in question is not involved with locating the spring perch on the axle and the spring. It is sandwiched between the perch and spring over the locating bolt. If the plate hole is too large, the plate could shift position a bit but the perch is still located.

 

[Kernel Sanders]

Have done this...
yes tack weld a washer in the big hole then you must drill for the relocation of the Ubolt location as the 73-74 use a big spring isolation contraption which moves the Ubolts out some.

here is my solution to using the 73-74 plate and eliminating the stupid rubber biscuit setup to use the earlier shock plates. Note the tacked in washer and the ubolt relocation holes drilled...

 

[Kernel Sanders]

Here is a pic of the plate used with the 73-74 8.75 axle which you will also note I had to weld in a washer to fill the big hole on the spring mount thus eliminating the ISO contraptions. Your 72 8.75 will already have the small hole on the spring mount so no need to modify yours.

 

[plymouthman72]

Thanks for all the replies, this helps me a lot! After I got the responses, I wanted to see exactly what I was working with and I actually found the other half of my plate, well most of it anyways. I went ahead and bought the 73's since I may need a back up but would you guys trust this for a fix? I am not finished welding yet but started it and cleaning it up but if this works, it would save me some time. I plan on welding smaller pieces to fill the completely missing areas. What do you all think? I just dont want something that will break on me.

 

[69b3rt]

You will need the contoured edge around the plate for strength or else it will bend and break at your weld area.

 

[plymouthman72]

You will need the contoured edge around the plate for strength or else it will bend and break at your weld area.

That was what I was thinking. Thats why I bought the back ups incase I can not get it close or good enough. It will be fun to try though. This is one of the first times I have tried to fabricate a repair. I am excited to at least try.

 

[Nacho-RT74]

I didn't know these were so hard to find!

yes they are... specially because was a one year only production!

73 and laters are "easier" what doesn't mean easy

 

[plymouthman72]

So I busted out my welder and grinder this weekend and attempted to fix my bracket and I am pretty stoked by the results. Its not perfect around the edges but its functional and straight along the top where it needs to be. I see now why you fab guys enjoy this so much. It may just be a bracket but I can't believe how much fun I had fixing it. Thanks for all the help guys and if this ever does fail, I will at least have the 73's for back up.
Here is my finished product and my home made paint booth ha!

 

[YY1]

Nice.