Topic: Carb spacer & gaskets - 68 S code

[WT8095]

The original S code motor was missing from my fastback when I received it. I have almost everything I need to put a correct motor together (still need some smog pieces). I have not seen what the carb spacer arrangement is on an original car, so I'm trying to piece together what it should be. There are some inconsistencies in descriptions in the '75 MPC, which I think I now have a handle on. Is this the correct combination, working from top down:

Carburetor
Gasket: C8OZ 9447-A (.125" fiber w/brass grommets)
Spacer: C8AZ 9A589-G (.28" plastic/bakelite?)
Gasket: C8SZ 9447-A (.018"/.024" fiber)
Manifold

Car was built in SJ on 2/7/1968.

The MPC lists the spacer as "F-High Performance", in contrast to most of the other 390GT-specific parts which are listed as F("GT w/4B carb) or simply F(w/4B carb). For years I didn't notice that listing, but many parts sites list the C8AZ-G for the 390GT. I now turn to the experts for their esteemed opinion 

[J_Speegle]

Checked a 4/68 printing of the MPC 


Spacer they listed as

Carb- to spacer gasket - C8OZ-9447-A as you listed. No description other than the 1.25 thickness

Stainless - C8AZX-9A589-C - the -G didn't exist it appears (no where to be found) at that time. The letter would suggest a later revision

Spacer to intake - Same as Big Ford 390 4V and non-PI 428 carb to spacer - Number you listed is the same

Didn't find an 390 High performance wording. Likely something added in the 7 years between when your MPC was printed and when the 68 version was

Have a couple dozen pictures of plastic carb spacers but none identified by either of the part numbers we've posted.

Did check WWC to see what they listed and they showed (out of stock) a reproduction spacer that was listed for both the 390 and the 428CJ  as well as 68 & 69

[WT8095]

Stainless - C8AZX-9A589-C - the -G didn't exist it appears (no where to be found) at that time. The letter would suggest a later revision

That's the item that's tripping me up - I've always interpreted the '75 MPC as indicating that the C8AZ 9A589-C spacer (stainless steel) was the correct one for this application. But I have not been able to find references to the -C, and sites like Mansfield and others list the -G.

Of course both part numbers, C8AZ 9A589-C and C8AZ 9A589-G are service part numbers. It's possible the service part may be entirely different from the original, as we all know. In the October 1968 Master Cross Reference List, C8AZ 9A589-C is listed as replacing C8AE 9A589-E. I can't find ANY references to that part number online!

Fordification has a reprint of TSB #85, Article 1283 - Momentary Engine Hesitation on Acceleration and/or Rough Engine Idle. http://www.fordification.com/tsb/viewtopic.php?f=3&t=519 The TSB has an illustration (attached) showing "C8AZ 9A589-C (metal spacer)" which matches the number you found and the one I originally thought was correct. Of course it's a service part # too.

Since I don't have access to any S code cars other than mine, and the books and web aren't 100% clear on the subject, I'm soliciting first-hand knowledge from those who have or have worked on original S codes.

[TLea]

I will check my 68 MPC tomorrow at the shop. I think I have a NOS stainless difuser, only one I've ever seen

[WT8095]

I will check my 68 MPC tomorrow at the shop. I think I have a NOS stainless difuser, only one I've ever seen

Super, thanks! If it's the correct piece for this application, I would love to see some photos. And then the question becomes: would you be willing to part with it? 

[J_Speegle]

You don't see the stainless ones often. Those "fingers" in the bore sure make it stand out and memorable when comparing it to the "normal" design Ford used

[WT8095]

You don't see the stainless ones often. Those "figures" in the bore sure make it stand out and memorable when comparing it to the "normal" design Ford used

By "figures" are you referring to the "tabs" in the front bores as shown in the line drawing I uploaded? Does the part actually look like the line drawing? I've never seen one in photos or in person.

[J_Speegle]

By "figures" are you referring to the "tabs" in the front bores as shown in the line drawing I uploaded? Does the part actually look like the line drawing? I've never seen one in photos or in person.

Meant to write "fingers"  Yes tow (approx) 3/8 x 1/2" tabs that stick into the bore - likely to mix/atomize the fuel better

[WT8095]

Meant to write "fingers"  Yes tow (approx) 3/8 x 1/2" tabs that stick into the bore - likely to mix/atomize the fuel better

Wow, that is unusual! I'm keeping my fingers (pun intended) crossed that Tim has one!

[J_Speegle]

Fordification has a reprint of TSB #85, Article 1283 - Momentary Engine Hesitation on Acceleration and/or Rough Engine Idle.  The TSB has an illustration (attached) showing "C8AZ 9A589-C (metal spacer)" which matches the number you found and the one I originally thought was correct. Of course it's a service part # too.

One thing that should be mentioned is the illustration does not show what Ford did at the assembly plants. Just the fix when the carburetor is warped (out of specifications

It does provide a look at the "spacer" being discussed - thanks

[WT8095]

One thing that should be mentioned is the illustration does not show what Ford did at the assembly plants. Just the fix when the carburetor is warped (out of specifications

Correct, good to note for those who haven't read the whole TSB. Someone (me) should post the entire thing as a separate topic. In addition to the gasket modification, it calls for enlarging a passage in the carb itself, and how this change was incorporated in carbs built after Dec. 1967. If the TSB isn't already posted in one of the forums, I'll post it.

[TLea]

[WT8095]

Thank you for posting the photo Tim! Now I know what the holy grail looks like 

So, per Jeff's documentation, and having seen them before, per the TSB, and per the MPC version I have, it seems like this should be the correct spacer for a 1968 390GT. Jeff, can you (or anyone else) confirm that this is what was installed in production? Were there any alternates (i.e. bakelite or plastic) based on date or plant? I've seen a number of 390GTs at shows, but the spacer isn't visible with the air cleaner on, and I've never asked owners about the spacer. And there seems to be virtually no knowledge online other than the repro parts suppliers, who are all showing the plastic spacer. So if the stainless one is truly correct, it would be great to document it here!

[sportyworty]

One thing that should be mentioned is the illustration does not show what Ford did at the assembly plants. Just the fix when the carburetor is warped (out of specifications

It does provide a look at the "spacer" being discussed - thanks

it was a proposed fix after thought not needed for a correct restoration.

[J_Speegle]