I have a question and a problem. I'm doing a 73 restoration that was an auto.  I'm changing it over to manual with 72 round top carbs and intake manifold.  It appears the carb linkage arm that runs from the firewall bracket to the intake manifold are different lengths.  I looked on the micro fisch and it does not indicate that they are different. The mfg date on my 73 is 3/73 not sure the mfg date on the 72 (I only have the engine & trans).  Attached are two pics.  The yellow one is the original one on the 73 connected to the flat tops the silver one it the same linkage arm attached to the 72 round tops.  Note the spacing between the firewall bracket and the upright angle bracket on the linkage arm.  Comments, suggestions, resolutions greatly appreciaated.

Thanks

Paul (z3beemer)

The linkage piece that mounts in the balance tube is very different between the round tops and the flat tops including the location of the slot where the shepherds hook connects. The round tops require a longer shepherds hook.

I'm not an expert at reading the parts fiche, but it seems to me they did use different parts. Goes like this:

12 ASSY-TORSION SHAFT A

18300-E4600  L241

18300-E4601  L24  7206

18300-N3300  L24  7207-7307

18300-N3600  L26  7308-7408

18300-N4310  L26  7409

I'm thinking you're looking for 18300-E4600 or E4601 which were used until 6/72. Your car came with 18300-N3300 which started in 7/72.

Thanks for the input.  I guess I'll post in the want ads and see if anyone has a linkage arm from a 72.  If not I may be able to cut the one I have, and weld a section in to make it longer.  I can also weld a short stub on the shepherd hook. If I can't find one, I may need to call on the group to get a few dimensions.  In the meantime, if anyone has a linkage arm from a 72 (round top carb), let me know.

Thanks

Paul

7 hours ago, z3beemer said:

 I may be able to cut the one I have, and weld a section in to make it longer.

As some guys here know, i'm also here to learn some english writing.. 😉   Hey Paul.. read your paper on the engine in the first pic.. hihi.. what kind of linkage? 

I don't have a good answer on your question, but overall.. there are A LOT of differences in these cars parts..  sigh..

Well, I decided I'm going to try to weld an extension in the one I have.  Can anyone who has a 72 Z with round top carbs provide me a few dimensions?  I would need an overall dimension from the top of the shepherd hook to the end of the rod, and a dimension from the top of the shepherd hook to the end of the hook (the part that connects to the carb linkage).  Thanks in advance.

 

Paul

IIRC the 73 part was shorter, because of the EGR set up. Do you have the old one from the 73 to measure?

I have two, one is 12.125" the other 12.5" overall. 

The one from the 73 is 10.75" 

You can get a rough idea of the difference between the two by looking at where on the intake manifolds the joint between the parts lands. Use the intake manifold and/or carb mounting bolts as reference markers. Using hoovered pics:

Here's the flat tops. Note that the linkage joint is about the center of the rear carb:

And here's the round tops. Note that the joint is further forward requiring the longer linkage piece: