Any "C" codes out there?

[Kit Sullivan]

When it comes to 71 429 Mustangs, it seems nearly all of them are "J" code...429 w/ ram air, which is understandable.

But the non ram-air 429s... The "C" codes...I just don't seem to see nearly as many.

How many are here?

 

[Don65Stang]

I never understood why the 429 cars got a J or a C depending on the Ram Air option. Seems like a couple of my 351C Mach 1s could be more valuable if they had a different letter b/c of that same option.

 

[VegasFastback]

I never understood why the 429 cars got a J or a C depending on the Ram Air option. Seems like a couple of my 351C Mach 1s could be more valuable if they had a different letter b/c of that same option.

It was more than just the ram air option. Parts rotating assembly in the super cobra jet, the j code, were stronger than the c code.

 

[Mike429cj]

When it comes to 71 429 Mustangs, it seems nearly all of them are "J" code...429 w/ ram air, which is understandable.

But the non ram-air 429s... The "C" codes...I just don't seem to see nearly as many.

How many are here?

I have only seen one that was for sale a few years ago here in Houston. In was for sale at a place called Corvettes and Classics. They went out of business a year or so ago. Guess everyone wanted the Ram Air!

 

[Kit Sullivan]

Ok, a little confusion here:

J does not represent SCJ status, and C does not represent only CJ status.

To be a Super Cobra Jet, you had to order either the 3.91 ( Trak-lock)or 4.11 ( Detroit No Spin)axle...that automatically set you up with the SCJ version of the engine and gave you SCJ status.

That could be ordered on either the J or the C code 429 engines.

It was possible to have a SCJ with an J code ( ram air) as well as a C code ( non ram air) 429.

I agree, seems confusing and a little stupid to me:

Why have a seperate engine code for an engine that literally only has a different air cleaner on it?

There are NO other differences between a J code and a C code.

And, why didn't they use a different engine code when the " drag pack" option resulted in a considerably different engine?

Always seemed a little odd to me.

As far as I know, the only way to authenticate a factory SCJ is by verifying the axle ratio tag/ code in conjunction with either a J or a C engine code.

 

[cobra3073]

I agree that there is some confusion as it relates to CJ versus SCJ.

However, the differences are a bit more than just the ram air.

For example:

CJ have hydraulic camshaft while the SCJ has a mechanical camshaft.

The blocks are also different as the SCJ blocks have 4 bolt mains (there have been some cases where CJ blocks apparently received the 4 bolt mains).

The carburetor are different as the CJ got a Rochester while the SCJ has a Holley

Heads are different as the CJ has a positive stop threaded stud which was not adjustable while the SCJ heads has a non-positive stop thread that allows for adjustment.

...my $.02.

BT

 

[Don65Stang]

I knew it was more than a just ram air option but admittedly didn't know all the differences that BT stated.

 

[TommyK]

I was always under the impression that the C and J code designations simply meant ram-air or non ram-air and had nothing to do with which engine option (SCJ or CJ) was selected.

 

[Kit Sullivan]

Ok, again...there is confusion here:

The "Super Cobra Jet" version of the 429 engine is considerably more stout than the "Cobra Jet" 429: solid lifters and mechanical cam, different intake and Holley carb, nodular crank.

"SCJ" status would be conferred on either a J code or a C code 429 when either a 3.91 or 4.11 axle was ordered.

J code or C code had NOTHING to do with CJ vs SCJ status.

C code denoted a 429 Cobra Jet OR Super Cobra Jet( without ram air)

J code denoted a 429 Cobra Jet OR Super Cobra Jet w/ ram air

Either 429 engine ( J code or C code) would be upgraded to "Super Cobra Jet" status by ordering either the 3.91 or 4.11 axle.

So...there were 4 possible variations of the 429:

1) 429 CJ, NO ram air (C code)

2) 429 CJ, with ram air ( J code)

3) 429 SCJ, NO ram air (C code)

4) 429 SCJ, with ram air ( J code)

As you can see, "J" or "C" codes will NOT tell you if it is a Cobra Jet or a Super Cobra Jet.

There are many people over the years (MCA judges included) that just cannot seem to grasp this concept.

 

[cobra3073]

I agree with Kit as to the designations relative to "C" and "J" coded 1971 Mach 1s being essentially a difference in whether or not the car came with the ram air.

I think the confusion lies when we start speaking of CJ versus SCJ ENGINES. The SCJ designations speaks primarily to the Drag Pack option.

It comes down to whether or not the "C" Coded Mustang or the "J" coded Mustang was ordered with the drag pack option which mandated the 3.91 or 4.11 rear, the four bolted block, the adjustable rocker arms, mechanical cam, ect.

Over the years (as Kit stated and Tommy inferred), a lot of folks have come to confuse "C" coded Mustang with just CJ engines and J Coded Mustang with just SCJ engines.

Hope this does not add to the confusion.

BT

 

[Kit Sullivan]

I think what adds a bit to the confusion is that Ford did not follow the same formula with the 351 variations: any 351 2V ( 71-73) and any 351-4V ( 71 only) could be ordered with ram-air as a free-standing option( except BOSS 351, which included ram-air), which did not affect the engine codes in any way...as it should have been.

Why they didn't use this method with the 429s makes no sense.

 

[Mike429cj]

One other thing should be mentioned about the CJ / SCJ versions of the 429 Mustangs. If you ordered the Drag Pack option you could NOT order Selectaire Air Conditioning! That would not work good in Texas! If you did order a 429CJ with A\C you automatically got 3.25 gears.

I am sure you all know that if you ordered a 1971 Boss 351 you also could not get one with air conditioning. However, I believe that I did read about one that was made with The Selectaire Air option. I thing if I remember right it was for a Ford executive but not sure.

 

[Kit Sullivan]

Yes, apparently Ford felt that cars with the higher ( numerically) axle ratios would spin up the accesory pullies too quickly and run at higher RPM than what the a/c compressor clutches could reliably tolerate under warranty conditions, so...not available!

That is the primary reason I did not get an SCJ when I bought mine.

Plus, I really didnt think a 3.91 ir a 4.11 was optimal for a daily driver.

The 3.25s are great...perform great, and give good highway 75mph cruising with no effort.

My Z28 had 3.73s,/ 4-speed, and even that was a tad too stout for any extended hiway driving over 60-65 mph. But, boy howdy, what a kick-ass fun car that one was!

 

[Mike429cj]

Yes, apparently Ford felt that cars with the higher ( numerically) axle ratios would spin up the accesory pullies too quickly and run at higher RPM than what the a/c compressor clutches could reliably tolerate under warranty conditions, so...not available!

That is the primary reason I did not get an SCJ when I bought mine.

Plus, I really didnt think a 3.91 ir a 4.11 was optimal for a daily driver.

The 3.25s are great...perform great, and give good highway 75mph cruising with no effort.

My Z28 had 3.73s,/ 4-speed, and even that was a tad too stout for any extended hiway driving over 60-65 mph. But, boy howdy, what a kick-ass fun car that one was!

Oh yeah, one thing I forgot to mention, that 429 even with the 3.25 gears (if that is what I really have) really drinks the gas! I used half a tank going from Tomball to Humble. If this were a daily driver I would spend a fortune in fuel. What did your care average in MPG back in the day when you drove it all the time?

 

[Kit Sullivan]

With a stock drivetrain I averaged about 11mpg. If I babied it, which I did nost of the time, I could get up to 13-14.

With the new engine build, It averages 16 overall, and is much smoither and quicker...a great improvement.

This is the new engine set-up:

Compression lowered with 10.5 pistons, modern Comp-Cams cam, low-tension bee-hive springs, original CJ heads stored, now running worked 73 PI heads, extrude-honed exhaust manifolds, 2.5" exhaust.

It runs cooler than stock, is quicker to 60, pulls harder in mid-range, quicker 1/4mile ets, better mileage, much smoother idle, and is even a little quieter.

Dyno'd at 425 hp, 500 torque.

I had a 460 built to the same general specs for my Torino.

I love it.