1969 GT350 Carburetor Spacer

[nightmist67]

What is the correct carburetor spacer (carburetor to intake manifold) for the 351W engine on a 1969 GT350?  During teardown of the engine I removed a carburetor spacer (black plastic with a bent metal tube) that is listed in the NPD catalog as being used on Boss 302 engines.

[Bob Gaines]

What is the correct carburetor spacer (carburetor to intake manifold) for the 351W engine on a 1969 GT350?  During teardown of the engine I removed a carburetor spacer (black plastic with a bent metal tube) that is listed in the NPD catalog as being used on Boss 302 engines.

The Boss 302 tube may have been used on the later GT350 engines built after the end of March 1969 but typically the spacer was the same as used in 1968 GT350 and had a short straight nipple. The longer tube Boss 302 spacer was a a improvement in design that helped in attaching the hose to the hard to reach short nipple hidden underneath the bowls of a Holley carb. The Boss 302 spacer has always been the go to replacement because the other short style was obsoleted by 1970. I have not found conclusive evidence like on a later 351W survivor car that the long tube spacer was assemblyline. The 351W used the 4300 carburator that didn't have the bowl obstruction like the  Holley. I would be a little surprised that Ford would keep both in production when the longer style would work on both  but maybe it was cheaper. The short nipple style is prone to breakage which is why it was very commonly replaced.  Vin man is a original 69 GT350 owner I wonder if his has been replaced or not and what it is? 

[nightmist67]

Does the short nipple design use a 1" aluminum carburetor spacer?

[Bob Gaines]

Does the short nipple design use a 1" aluminum carburetor spacer?

No aluminum. It is thin plastic/bakelite material like the Boss 302 spacer. The main differance being the nipple design. That is why the Boss 302 spacer is the next best thing to assemblyline because it is so close in appearance. Besides that many 69/70 GT350 carbs have been replaced with the Holley carb (because the 4300 sucks IMO) so the longer tube/nipple style is needed there.

[J_Speegle]

+1 on the likelihood of the Boss style being installed on later examples after the Boss 302 was first built.

Believe this was the subject of at least one thread before the crash and included pictures from me and others. Unfortunately lost now

The version or at least the style seen most often is the bakeolite with metal nipple similar or same as in the upper right and lower left below

B9AE, C3AE -C, C8AE-D and C8AZ-E spacers

[shelbymann1970]

This is another case where I'll say my original engine on a May 6th built car has the straight tube and I believe it is original to my car as is the carb and throttle bracket.  If a later built car had a bad spacer then what would it get? The B2 style most likely as the service item. Gary

[Bob Gaines]

This is another case where I'll say my original engine on a May 6th built car has the straight tube and I believe it is original to my car as is the carb and throttle bracket.  If a later built car had a bad spacer then what would it get? The B2 style most likely as the service item. Gary

I would not be surprised. The B2 is the go to service replacement for a short straight one.

[J_Speegle]

This is another case where I'll say my original engine on a May 6th built car has the straight tube and I believe it is original to my car as is the carb and throttle bracket.  If a later built car had a bad spacer then what would it get? The B2 style most likely as the service item. Gary

This is going to be one of those details where the date when the engine was assembled is more important than when the engine was built at least for comparison. Your build date at Dearborn is very close to the first push of the production Boss 302's and in turn when those engines were built also. Would not be surprised that a new part, possibly in limited supply at the beginning took some time to get into circulation.

As far as for replacement both part numbers for both plates remained active after the release of the new version for the Boss was introduced so it would have been a choice when it came time to replace one at a later date. The choice could be based on what the dealership had in stock and other factors

[nightmist67]

Which of the above carburetor spacers with a short straight nipple would be correct for a 1969 GT350 with a late December 1968 build date?

[Bob Gaines]

Which of the above carburetor spacers with a short straight nipple would be correct for a 1969 GT350 with a late December 1968 build date?

The one with the short straight metal nipple.

[nightmist67]

From the images above, there appear to be two that meet that criteria.  Of the two, is there one (upper right, lower left) specifically for my application?

[Bob Gaines]

From the images above, there appear to be two that meet that criteria.  Of the two, is there one (upper right, lower left) specifically for my application?

They are rare, hard to find ,like hens teeth, etc.  Once bolted down under the carburetor the nuance differences are indistinguishable. My advice is to get what you can find.

[shelbymann1970]

This is another case where I'll say my original engine on a May 6th built car has the straight tube and I believe it is original to my car as is the carb and throttle bracket.  If a later built car had a bad spacer then what would it get? The B2 style most likely as the service item. Gary

This is going to be one of those details where the date when the engine was assembled is more important than when the engine was built at least for comparison. Your build date at Dearborn is very close to the first push of the production Boss 302's and in turn when those engines were built also. Would not be surprised that a new part, possibly in limited supply at the beginning took some time to get into circulation.

As far as for replacement both part numbers for both plates remained active after the release of the new version for the Boss was introduced so it would have been a choice when it came time to replace one at a later date. The choice could be based on what the dealership had in stock and other factors

since I have not looked at an assembly date for my engine where is it stamped? All I remember is my numbers being on the back of the block and on the trans. My car has it's original-to 70-ED dist, carb,  but the valve covers appear to have been replaced since they have the rounded corners service ones on it (have a correct set).

[J_Speegle]

since I have not looked at an assembly date for my engine where is it stamped? All I remember is my numbers being on the back of the block and on the trans. My car has it's original-to 70-ED dist, carb,  but the valve covers appear to have been replaced since they have the rounded corners service ones on it (have a correct set).

Honestly don't know on that particular engine and don't have a picture of such. The machining date would be on the oil pan rail but your not going to see it with then engine together. Another place to find part of the final assembly date for the engine would be the date on the engine ID tag - the aluminum one in the upper right if I recall correctly. Hopefully that is still on your engine