Topic: Leaf spring cross reference - 68 J code GT High Country Special

[ruppstang]

Just to throw this in, from memory my rear springs are C7ZA 5556 AU. This is from a Non GT coupe with Heavy Duty Suspension option.

Tim from what I have found the Heavy Duty Suspension used the same leaf springs as the GT. I purchased a pair of AUs from a HDS car this week.
I am curious about one thing, are your shock towers welded on the inner structure? I have found most 68 GT small block cars to be welded.

[tim_morrison82]

Definately not welded on mine. Mid dec 67 san jose car.

[ruppstang]

Definately not welded on mine. Mid dec 67 san jose car.

 
Thanks I did not think it would be. It most likely has a 8 inch rear axel too. It is looking like the only small block that were welded were GTs.

[ruppstang]

It is interesting the difference in profile in even the short springs. The lightest one the Y has the most arc.
The AR seems to made by a different supplier as it is stamped differently and is shaped slightly different.   
Marty

[Bob Gaines]

It is interesting the difference in profile in even the short springs. The lightest one the Y has the most arc.
The AR seems to made by a different supplier as it is stamped differently and is shaped slightly different.   
Marty

I don't see a "AR" but do see a "AM" . It doesn't really matter from a comparison stand point because the AR and the AM were virtually identical in specs and design. the Au seems to be the different design . I have always thought the "E" at the end of the date code was the MFG mark for Eaton . Not to be confused with the Detroit Eaton that makes springs for the aftermarket because they are not related to the vintage OEM mfg.

[ruppstang]

Yep you are correct I meant AU.
I found a nice set of AUs out of a 68 GTCS with Heavy Duty Suspension. I all ways say its better to be lucky than good.

[sportyworty]

I have a set of 68 R code automatic springs and they are AM. Can check the J code GT 4 speed tomorrow as it has the original springs as well.

[ruppstang]

I have a set of 68 R code automatic springs and they are AM. Can check the J code GT 4 speed tomorrow as it has the original springs as well.

Kerry if you would also check your shock towers and see if they are welded like the big block cars.
Thanks Marty

[sportyworty]

Kerry if you would also check your shock towers and see if they are welded like the big block cars.
Thanks Marty

Hi Marty, I finally got a chance to look at the GT J code car. The leafs are both original to the car. With regards to the towers, the passenger side has a very typical looking stick weld with a piece of wire still in place. The driver side however is not welded. I cannot say with 100% certainty it has not be welded after leaving the San Jose plant but would say it is very doubtful based on the over all car and the history. Hope this is helpful for you.

Left/Right Leafs
Left/Right Towers

[ruppstang]

Thanks Kerry you car looks to be the same as several J codes I have gotten information from except the one unwelded  shock tower. I believe it was just missed. Does your car have a nine inch axel with a 3.25 open gearing? The 3.25 seems to be the most common in the cars I have looked at.
Marty   

[sportyworty]

It is a 4 speed with an optional axle code E limited slip 3.00 9 inch.

[tim_morrison82]

Just to clarify. I thought i remembered seeing 5556 in there somewhere. Now i see
C7ZA - AU
300EC7
 i didnt check the front side, just the rear. Is that correct? Both sides have the same stamp.

[ruppstang]

Tim they were only stamped in the rear on the ones I have seen. It seems that there were two manufacturers, one used the 5556 in the engineering number and the other did not.
Marty

[J_Speegle]

Tim they were only stamped in the rear on the ones I have seen. It seems that there were two manufacturers, one used the 5556 in the engineering number and the other did not.

+1 Different suppliers at the time and in the years to follow as we've seen examples of in this thread

[ruppstang]

I got the AU springs last week and am very pleased with them. I thought it was interesting that they appear to have been striped laying together. These came off a 68 C code GTCS with HD suspension witch show it was the same suspension used on the GTs.
Because of the original condition what would you recommend for clean up. I hate to just blast them and start over.
Marty