Topic: Correct rear shackles for 1968 dual exhaust car?

[ramblewood390GT]

I need to get a set of rear shackles for a 1968 GT car with dual exhaust. What would you recommend as the most correct among the new production stuff?

[Bob Gaines]

I need to get a set of rear shackles for a 1968 GT car with dual exhaust. What would you recommend as the most correct among the new production stuff?

Good question . I have seen the special  duel exhaust shackle for the driver side only sold separately and not part of a matching set . It is only similar in appearance compared to a original. Big surprise. That special one that is made staggered doesn't match the standard side sold separately in materials and over all appearance. That was NPD.  Maybe other dealers have different. Hopefully someone else has had better luck. I made my own using originals as donor parts rather then waste anymore time. FYI you need two good used ones (pre 1970 style) to make one duel exhaust staggered shackle.  You press out one shaft from each of two separate shackles . You fit together the two one shaft half's for a complete look.  The nut typically covers any irregularities from where the shaft was pressed out. You can't do this with the later style service replacements. Starting in 1970 I believe the shackle shaft became a larger diameter compared to 65-69. The shaft necks down to the same thread size as 65-67. If you press out the shaft of the later style the resulting hole is too large for the nut . The old rubber bushings will not work on the newer Ford service shackle ether because they have too small  diameter hole.     

[jwc66k]

I made my own using originals as donor parts rather then waste anymore time. FYI you need two good used ones (pre 1970 style) to make one duel exhaust staggered shackle.     

The dual exhaust type is the same for 66 thru 70, all used 1/2 inch dia shafts (64-65 are 9/16 inch dia).

You press out one shaft from each of two separate shackles . You fit together the two one shaft half's for a complete look. 

You need to drill out one of the mounting holes of the bar to press fit the shaft, and you need to do this to two bars (sorry, I can't remember the exact size, I think 1/2 inch - you should measure the knurled dia and make a slightly smaller hole). I phosphated the bars, clear zinc plated the shafts then pressed the shaft in the renamed plates.
The NPD pictures show a faint stamped ridge (I can't think of a good word) around the dome of the bar and plate about 1 1/4 inch on both their single and dual exhaust shackles. Bob's concern about the two types matching is correct. Also be advised, there "may" be a partial Ford part number "C6DA" on original bars.
Jim

[ramblewood390GT]

Thank you for the advice. I'm sorry for starting the discussion in the wrong section. I'm pretty new to all this so even the most basic info is helpful to get me on the right track.

It sounds like I should get 4 original shackles and then create two staggered sets from those, for the most proper look?

[Bob Gaines]

Thank you for the advice. I'm sorry for starting the discussion in the wrong section. I'm pretty new to all this so even the most basic info is helpful to get me on the right track.

It sounds like I should get 4 original shackles and then create two staggered sets from those, for the most proper look?

Only need three. You need the staggered shackle (duel exhaust only) on the driver side only. The passenger side is normal. Two to make the special one and one for the for the passenger side.

[ramblewood390GT]

Thanks Bob. I'll look for a set of 3 with a similar level of wear and break out the drill. Seems like a project I can handle.

[Bob Gaines]

Thanks Bob. I'll look for a set of 3 with a similar level of wear and break out the drill. Seems like a project I can handle.

There is no drill needed for the way I described to make the staggered shackle but you will need a hydraulic press to push one shaft out of each of the donor shackles to make the two half's. To do it Jim's way you will only need the one shackle but you will need the drill and the hydraulic press. That is because besides pressing out the one side shaft you will then re install the loose pressed out shaft into the end plate (end plate with two holes) of your one single shackle . You have to enlarge one of the two holes in the end plate to accept the previously pressed out shaft. After pressing in the knurled end of the shaft into the drilled out hole you have made your other half.  The end result is the same just different ways to achieve it. My way has less steps but you need more parts (two shackles). Jim's way uses less parts (one shackle) but more steps. I typically do it the way Jim describes because it uses less parts but it is a little harder to do. I explained the other way procedure using the two to make one because it takes fewer steps and it is easier. It will be up to you to decide which way to do it . 

[ruppstang]

I have not seen the duel exhaust shackle used on 68's. I have a unrestored 12/02/67 built 68 Shelby that does not have the duel shackle.
Am I wrong?

[CharlesTurner]

I have not seen the duel exhaust shackle used on 68's. I have a unrestored 12/02/67 built 68 Shelby that does not have the duel shackle.
Am I wrong?

I was going to add that I don't believe all dual exhaust cars had them.  Maybe one of those 'should have had', but like a lot of things we see, wasn't an absolute.

[CharlesTurner]

I phosphated the bars, clear zinc plated the shafts then pressed the shaft in the renamed plates.

Jim, I've seen the bars as natural steel, I blast/tumble them to get the correct appearance (so long as they aren't heavily pitted).  The shafts are usually phosphate or just a darkened heat-treated.  There may be variances based on assembly plant or year, but this has been pretty consistent with originals I've found.  I know the repro's come the way you've described, but they don't match originals (at least what I've seen).

[TLea]

I'm going throw a big wet blanket on the staggered shackle myth. I've taken apart probably 30-40 68/69 dual exhaust cars and never seen any staggered studs. If it were my car I would use same shackle left and right.

[specialed]

I have never seen staggered shakles on any 68s either & 70s were a one year only coarse thread & shoulder nuts then 71 up back to fine thread with the thick plates from what I seen. I have found the c6da #s on west coast cars.

[Bob Gaines]

In all fairness I agree with Ed and Tim and the others. I believe the special staggered shackle on the driver stopped after 67 production. In my effort to help with the "duel exhaust shackle" I should have mentioned that although duel exhaust the evidence goes against the special shackle being used on the later cars. Sorry for the confusion.   

[ramblewood390GT]

Sorry for the confusion.

I'm happy. Less work for me and I learned some new stuff. Do these look ok?

https://www.ebay.com/itm/-/222396277112?

[jwc66k]

I've seen the bars as natural steel,

Rusts.

I blast/tumble them to get the correct appearance (so long as they aren't heavily pitted). 

I don't have a tumbler big enough, in fact not many do. I blast.

The shafts are usually phosphate or just a darkened heat-treated. 

Possible. When I removed the rubber bushings on a known original pair and saw what appeared to be clear zinc, and confirmed it when the shafts were removed, I assumed they were clear zinc plated. Supplier difference may be the reason.

I have never seen staggered shakles on any 68s either -

That would be best answered by 68 Shelby owners. Calling 68 Shelby owners.
Some pictures of the bar used on the left hand side duAl exhaust cars, and both sides on all single exhaust cars. The part number for the bar is C4DA-5627-A.
Pic 1 - Seven from my collection. The top one is a Scott Drake reproduction. Original bars are 0.168 to 0.228 inch thick, S Drake's is 0.155 inch. Note the "rings" around the holes that approximate where the rubber bushing fits. The ring is part of the stamping tool for the "cup" of the bushing end. I believe the same bar was used into later years as the nuts used for the shafts are the same, which would be indicated by the same hole for the threaded part of the shaft, and the hole spacing is the same. That does not answer why the part is marked C6DA in pic 3. However, all the bars are all interchangeable with the double shaft plates I have. Keep in mind that the majority of cars is see in the San Jose, CA area were built in San Jose.
Note: The tape is to identify the bars when flipped -
Pic 2 - The same seven, flipped. Look carefully for markings. OK, don't. You will see them in the next three pictures.
Pic 3 - Marked C6DA
Pic 4 - Has an "E" stamped.
Pic 5 - Has an "E" stamped, it's now not a coincidence. The other four have no markings (just some pitting where the bushings rub).
Jim
Note the smaller four "notches" on the one in the second row, right hand side.