Can anyone tell me what Intake Manifold this would have been fitted to thanks DIZE-9425-BB Holley Carby Base?

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
1971 351 Cleveland, 4 barrel spreadbore Autolite/Motorcraft 4300 carb.
Disagree. NOT 71. It's a 72/73 spread bore for a 4300D carb.
EDIT: I just looked up that part number on Mustangtek.com (actually a print out) It does list for a 71 CJ Mustang as well as 72/73CJ. If it's a 71, then it was a very late one, just before the year switch over.
EDIT 2: I rechecked the Mustangtek info and it has a question mark besides 73. Not all info listed is known to be correct, As Hemikiller shows, the 73 is different and has the EGR change.
 
Last edited:
Hi, hoping someone may be able to tell me what this would have fitted to thanks, Monty

That's the factory intake for a 71-72 351CJ engine (Q-code). The casting date on yours (1M23) is Dec 23, 1971, so it was installed in a 1972 model year car. The same intake was used for all 351CJ engines in '72, so it could have been originally installed in a Mustang, Cougar, Torino or Montego.


D1ZE intake is 71-72 351CJ, used with Autolite 4300D carb.

1678200466851.png

D3ZE intake is 73-74 351CJ, and equipped with the EGR system. It also mated to an Autolite 4300D carb.

1678200507282.png
 
That's the factory intake for a 71-72 351CJ engine (Q-code). The casting date on yours (1M23) is Dec 23, 1971, so it was installed in a 1972 model year car. The same intake was used for all 351CJ engines in '72, so it could have been originally installed in a Mustang, Cougar, Torino or Montego.


D1ZE intake is 71-72 351CJ, used with Autolite 4300D carb.

View attachment 74190

D3ZE intake is 73-74 351CJ, and equipped with the EGR system. It also mated to an Autolite 4300D carb.

View attachment 74191

I will confirm the second photo is for '73. I currently have mine apart for 4300D carb replacement -- still trying to find a way around the EGR (exhaust gas) channel. 71-72 looks like it would be covered by the carb, whereas the 73 arcs out past the normal edge of the carb.
 
I will confirm the second photo is for '73. I currently have mine apart for 4300D carb replacement -- still trying to find a way around the EGR (exhaust gas) channel. 71-72 looks like it would be covered by the carb, whereas the 73 arcs out past the normal edge of the carb.
I'm not sure if an adaptor plate is made for that, but for me, I would just make my own........... if I still had access to a machine shop. Retiring has it's downfalls.
Not being familiar with 73's, I believe the frame mounts were lowered to allow for the EGR plate thickness, therefore keeping the top of the carb at the same height for the Ram Air assembly. If that's is the case, then an adaptor plate the same thickness as the EGR plate will work. However, it it was me I'd seal off the exhaust duct in the manifold as well. You don't want heat up there under the carb any more, especially if you decide to ditch the 4300D, which would be my choice. I'd drop a Holley 670 or QF about the same cfm on it.
 
Last edited:
I'm not sure if an adaptor plate is made for that, but for me, I would just make my own........... if I still had access to a machine shop. Retiring has it's downfalls.
Not being familiar with 73's, I believe the frame mounts were lowered to allow for the EGR plate thickness, therefore keeping the top of the carb at the same height for the Ram Air assembly. If that's is the case, then an adaptor plate the same thickness as the EGR plate will work. However, it it was me I'd seal off the exhaust duct in the manifold as well. You don't want heat up there under the carb any more, especially if you decide to ditch the 4300D, which would be my choice. I'd drop a Holley 670 or QF about the same cfm on it.
That explains the difference in 71-72 and 73 motor mounts! Thanks. And you've highlighted my concern: even if I cover up the exhaust duct and outlet, it will still be getting exhaust (heat) there. Suggestions? Does that mean pulling the manifold? Right now the spread-to-square bore adapter is the same thickness as the EGR plate, but, doesn't cover the exhaust duct and, with the EGR plate in place, raises the carb beyond the reach of the attachment bolts.

Summit says they have the right adapter and it should be arriving today.
 
That explains the difference in 71-72 and 73 motor mounts! Thanks. And you've highlighted my concern: even if I cover up the exhaust duct and outlet, it will still be getting exhaust (heat) there. Suggestions? Does that mean pulling the manifold? Right now the spread-to-square bore adapter is the same thickness as the EGR plate, but, doesn't cover the exhaust duct and, with the EGR plate in place, raises the carb beyond the reach of the attachment bolts.

Summit says they have the right adapter and it should be arriving today.
Again, as I have zero knowledge of the 73's, all I can relate to is what I did on my 71 intake to eliminate the exhaust heat cross over. May be it will help, maybe not.
At first, I tapped the two ports and inserted 5/16" set screws. That helped but the intake was still too hot for the carb, Holley 670. I ended up pulling the intake and blocking off from the inside. I'll not go into full details here, but here is a pic of one of the two ports I blocked off. Maybe it will give some idea of what you might need to do.
 

Attachments

  • IMG_2851_LI.jpg
    IMG_2851_LI.jpg
    3.1 MB · Views: 0
  • IMG_0639_LI.jpg
    IMG_0639_LI.jpg
    5.4 MB · Views: 1
The Mustangtek site is a good source for helping ID Ford engineering numbers, but it is not always 100% accurate. The D1ZE-BB cast iron spread bore intake was initially released for the '71 351 CJ, which became available for the dealers to order in May '71. A D2ZZ-9424-A (D2ZE-AA) intake was also listed for the 72 Q code engines. I've seen D1ZE and D2ZE versions of these intakes in the shop and salvage yards when "Treasure" hunting on '72 351 CJ "Q" engines. I have a D1ZE intake with a 71D29 date (April 29, '71), so the date codes run the spectrum on '71 and '72 Q code production. These intakes were used in Mustang, Cougar, Gran Torino, Montego, Torino/Montego "Trooper" police package, and Panteras.

Some techs blocked off the heat passage on the D3ZE intakes. (This was before it was considered "Tampering" by the Feds). Because of the EGR spacer plate, the intake pad has a larger "Footprint" that would prevent bolting a carburetor directly to it. The original aluminum EGR spacer plates were notorious for burning out, and the cast iron replacements did fix that problem. But many owners, tired of dealing with the spacer plate issue and the engine strangeling EGR and emissions issues, just blocked the intake heat passages and pulled the vacuum lines off the EGR valve.

The air cleaner housings were adjusted in '73 to compensate for the increased height of the carburetor due to the EGR spacer plates. The motor mounts were redesigned in '73 as "Capture" style mounts, which altered their height compared to the '71-72 style. This was a safety issue since many vehicles were still running throttle linkages (instead of cables), which would tend to lock the engine in at WOT if the mount(s) broke during heavy acceleration. This was a bad problem with GM vehicles in the '60s and 70s. I did have one in a '69 428 SCJ Cyclone to break and cause my butt cheeks to pinch a hunk out of the seat before I got it stopped! Unlike the accelerator cable used on the '71-73 Mustangs, the Cyclone had the throttle linkage and loved to pull the driver-side mount apart. The new '73 style mounts were a good start on the safety issues the Feds were now watching closely. :)
 
The Mustangtek site is a good source for helping ID Ford engineering numbers, but it is not always 100% accurate. The D1ZE-BB cast iron spread bore intake was initially released for the '71 351 CJ, which became available for the dealers to order in May '71. A D2ZZ-9424-A (D2ZE-AA) intake was also listed for the 72 Q code engines. I've seen D1ZE and D2ZE versions of these intakes in the shop and salvage yards when "Treasure" hunting on '72 351 CJ "Q" engines. I have a D1ZE intake with a 71D29 date (April 29, '71), so the date codes run the spectrum on '71 and '72 Q code production. These intakes were used in Mustang, Cougar, Gran Torino, Montego, Torino/Montego "Trooper" police package, and Panteras.

Some techs blocked off the heat passage on the D3ZE intakes. (This was before it was considered "Tampering" by the Feds). Because of the EGR spacer plate, the intake pad has a larger "Footprint" that would prevent bolting a carburetor directly to it. The original aluminum EGR spacer plates were notorious for burning out, and the cast iron replacements did fix that problem. But many owners, tired of dealing with the spacer plate issue and the engine strangeling EGR and emissions issues, just blocked the intake heat passages and pulled the vacuum lines off the EGR valve.

The air cleaner housings were adjusted in '73 to compensate for the increased height of the carburetor due to the EGR spacer plates. The '73 motor mounts were redesigned in '73 as "Capture" style mounts, which altered their height compared to the '71-72 style. This was a safety issue since many vehicles were still running throttle linkages (instead of cables), which would tend to lock the engine in at WOT if the mount(s) broke during heavy acceleration. This was a bad problem with GM vehicles in the '60s and 70s. I did have one in a '69 428 SCJ Cyclone to break and cause my butt cheeks to pinch a hunk out of the seat before I got it stopped! Unlike the accelerator cable used on the '71-73 Mustangs, the Cyclone had the throttle linkage and loved to pull the driver-side mount apart. The new '73 style mounts were a good start on the safety issues the Feds were now watching closely. :)
Great info as always Steve.
Can you elaborate on the frame mount height difference? As I said many time, I know nothing about the 73's , but interested to learn.
 
I don’t know how much lower the stock 73 mounts place the motor, but before I did my 87 TBird swap into my 73, with the get-40 intake, a few folks told me I would have hood clearance with that taller intake. As I finally determined, installed engine had no clearance issues. In fact, it had room to spare. So, those 73 capture engine mounts must be quite a bit lower than the 71-72 mounts.
 
Hey Geoff,
My apologies to Monty for the slight highjack of his intake question. I bet this is more than he ever thought he wanted to know about intakes, motor mounts, and brackets!
Geoff, the closest I've come to owning a '73 was a Mach 1 parts car I acquired a few years ago. I'll give it to the engineers; there were a lot of safety and emissions-related changes they blended into a vehicle in its final months of production. The "Captive" motor mounts were badly needed.
With the extra hardware needed to make them compliant, they were actually taller than the '71-72 mounts. Since the EGR spacer plate had already increased engine height, Ford compensated for the taller mount by lowering the frame brkt/perch. Because of the differences between the '71-72 and the '73 mounts and brackets, they will not interchange.
With sales slow to non-existent on these one-year-only parts, they were only in the parts system for a short time. Sales were slow enough on the vert mount and brkt; they were discontinued in '79, long before the final issue '73-79 Ford Master Parts catalog was printed in 11/88. Until a rebuild service became available for the '73 mounts, many owners were forced to use '71-72 style brackets and mounts.
The illustration below shows the difference between the '71-2 and '73 left-side brackets for the Hardtop (Coupe) and Sportsroof.


1678261327686.png
 
Hey Geoff,
My apologies to Monty for the slight highjack of his intake question. I bet this is more than he ever thought he wanted to know about intakes, motor mounts, and brackets!
Geoff, the closest I've come to owning a '73 was a Mach 1 parts car I acquired a few years ago. I'll give it to the engineers; there were a lot of safety and emissions-related changes they blended into a vehicle in its final months of production. The "Captive" motor mounts were badly needed.
With the extra hardware needed to make them compliant, they were actually taller than the '71-72 mounts. Since the EGR spacer plate had already increased engine height, Ford compensated for the taller mount by lowering the frame brkt/perch. Because of the differences between the '71-72 and the '73 mounts and brackets, they will not interchange.
With sales slow to non-existent on these one-year-only parts, they were only in the parts system for a short time. Sales were slow enough on the vert mount and brkt; they were discontinued in '79, long before the final issue '73-79 Ford Master Parts catalog was printed in 11/88. Until a rebuild service became available for the '73 mounts, many owners were forced to use '71-72 style brackets and mounts.
The illustration below shows the difference between the '71-2 and '73 left-side brackets for the Hardtop (Coupe) and Sportsroof.


View attachment 74213
Steve, thank you. That is great information and you confirm what I thought, the 73 frame mounts/perches were lower to drop the motor to allow for the egr plate and the new mounts for the 351C.
 
That explains the difference in 71-72 and 73 motor mounts! Thanks. And you've highlighted my concern: even if I cover up the exhaust duct and outlet, it will still be getting exhaust (heat) there. Suggestions? Does that mean pulling the manifold? Right now the spread-to-square bore adapter is the same thickness as the EGR plate, but, doesn't cover the exhaust duct and, with the EGR plate in place, raises the carb beyond the reach of the attachment bolts.

Summit says they have the right adapter and it should be arriving today.
Did Summit provide a part number for the adapter? Please let me know if it worked. I'm wanting to change out my 4300D to a Holley 4160.
 
Back
Top