How can i tell a CJ 351 from a reg Cleveland 351

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Hello batwrangler,
I assume you are referring to the 351 4bl VS 351CJ debate.
The difference....not a lot.
It's was all a name game with some creative terminology by Ford and the other manufactures. The engines did receive engineering upgrades to make them compliant with each current model year emissions requirements. The '72 Q engine content never changed in '72, which is also when the engine's name changed. I owned a 12/71 built '72 Q code Gran Torino which had the chrome CJ air cleaner lid and CJ on all the paperwork. My 5/72 built Q code '72 Sport had 351 4Bl on a chrome air cleaner lid and other paperwork. Same engines, but a well-orchestrated game was going on with the renaming of these engines. The 65-72 Ford Master parts catalog (MPC) identified the 351 Q as a CJ. The 73-79 catalog referred to the 351 Q as a 351 4bl. There were some occasional references to the CJ engine in some 73-74 service manuals, but the shop techs knew they were all "Q" engines regardless of what someone called them. The 71-74 engines used the same style block (machined for 2 or 4 bolt mains), crank, cam, springs, etc., with the 73-74 engines receiving cylinder head, intake, and piston changes to accommodate the new EGR systems. The manufactures desire to move away from any reference to performance had a lot to do with the CJ name disappearance from air cleaner lids, window stickers, and all other printed matter. With gas prices changing almost hourly, economy, not performance, was the new word for the day! The government was always busy protecting us from ourselves, and the insurance companies watched the Big Three closely. They wanted to make sure we were offered cars with the same excitement level of a new toaster oven but were slow, safe, and got better fuel mileage than those fuel guzzling loud performance cars we all loved!
Hope this is the answer you were looking for. If not, will have to hit the reset button and start over!   :biggrin:

 
Wow Steve Thanks that was great i do have a chrome valve covers that say Ford on it  ,,i understand they were trying to down play the muscle car replace it with Graphics,,,so ill have to research some more other then that im going to say its a CJ motor

 

Don C

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The problem with trying to use the heads alone is that the same casting numbers were used on "regular" Clevelands and on CJs. I have a set of 1973 CJ (Q code) heads that have the D1ZE DA casting number dated May 11, 1972, and have 2.19 and 1.71 inch valves. Later 1973 CJ heads were D3ZE-AA with 2.04 and 1.66 inch valves. The D1ZE DA heads I have also have the 4 with a dot (ball) in the corner and are open chamber. The casting numbers are on the under-side of the intake ports and require removing the intake manifold to see them.

The '73 CJ block I have has a casting number of D2AE CA, which is a 4-bolt block and casting number. However, the block casting numbers are not always a good indicator, either. All Cleveland blocks could be either 2- or 4-bolt, by selection of the main bearing caps.

The best way is to find out if you have a 4-bolt block, which was generally used on only the CJs, although there were some "regular" Clevelands that had 4-bolt blocks. The easiest way is to drain the oil and use a bore scope to look at the main bearing caps, to see if they are 2- or 4-bolt.

 

Hemikiller

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Is their any thing on the heads that would show a difference between 351 CJ and 351 Cleveland
Ford only built one 351-4V engine in 73, and while the "CJ" name was applied in different ways, they are all the same.

 
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Hello Batwrangler,
You should have enough info now to verify what heritage your '73 has.
Your chrome "Powered By Ford" valve covers are more than likely chrome plated original blue covers. There were no standard or optional chrome valve covers offered by Ford for the '71-73s. The closest production cover would be the chrome "Powered By Ford" valve covers on the '69 Boss 302 and some early production '70 Boss cars. They had the oiling fingers since those were solid lifter engines. To my knowledge, Ford never released a service part number for these and was discontinued when the finned aluminum covers were released that we usually see on '70 302 and '71 Boss 351 engines. These are rare valve covers.
I won't get into the numerous part and engineering numbers on the pre '73 engines as you can about drown in a soup of numbers. As Don C mentioned, occasionally, Ford would use a casting number for other applications, which would drive number chasers crazy. I've witnessed some very heated discussions between some Boss 351 owners who claim to have found different ID numbers on their original engines.
Checking for cylinder head identification can be as much as a PIA as finding out what our Government is hiding in area 51. As Don noted, it required pulling the intake as the ID is under the intake port on the head. I bet the engineers still get a good chuckle over that.  
If your engine is original to your Mach 1, then the heads would be marked D3ZE-AA. That head had the 4bl port size, smaller 2bl valves, and a 75.4cc combustion chamber. (CC number varies by information source).
The price of the illuminated I phone scopes has come down where they are now an affordable tool and can be used as Don suggested doing a main cap bolt count. Unless your vehicle had an engine change or some Ford repair work at some time, then you should get some good answers. At the end of 351C production, the D0AZ-6010-C (2 bolt block) became the service replacement block as inventory was depleted. You can verify your engine as OE by checking the left rear of the block right below where the cylinder head mates to the block. If original, there should be a partial VIN starting with "3F" and the six numbers from your consecutive serial number. A good light, mirror, or camera/phone, and the skills of a contortionist will help. Just a word of caution, don't think you are going blind if you can't read them easily. Some were stamped perfectly legible, and some you couldn't read with the engine out of the car.
Good luck with your mission!  :classic_smile:

Vin-partial-block.jpg

 
This some great info im going to try and get to the back of engine for a pic is a pic of valve cover noting {Their hard to find } im going to keep them on,,thanks again this will keep me working for a while

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Spike Morelli

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Batwrangler, 

                  The rocker covers that Secluff was referring to, which were used on the Boss 302, are different than what you have in your photo. Yours are replacement "Ford Motorsport" embossed, while the Boss covers say "Power By Ford", and have the oil dripper fingers to help lubricate the adjustable rockers used with the Boss. those metal drippers will interfere with other than the factory designed rocker, so it is likely that the "Motorsport" covers will not have the solid cam rocker drippers. The Ford factory Boss 302/351 finned aluminum covers will also incorporate the oil drippers. Most aftermarket close copies will not. Big block Chevrolets had drippers spot welded onto the insides of their stock rocker covers for the same reasons, and suffer the same fate as Fords, in that the aftermarket BBC chrome covers don't have them, and like Ford, the drippers would get in the way of aftermarket rockers. For that matter, lots of aftermarket rocker covers have oil fill/ breather baffles that hit the aftermarket rockers on most modified engines, requiring taller, or modified covers.

 
ok Boy Oh Boy I learned a lot today ,,Oil Dripping fingers ,,never knew about that too,,, heres a picture of what it looks like now new traction bars still wrapped

thumbnail.jfif

 

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Hello Batwrangler,   

It looks like before we get through with you, you'll know more than you ever thought you would want to know about these "Clydesdales." (and valve covers) :biggrin:   As Spike noted, the valve cover in your photo is the Ford Motorsport (now Ford Racing Parts) chrome cover that Motorsport sold for many years. I sold so many of those that I still remember the part # and sell price (M-6582-C351R @ $54.95)!  They were discontinued years ago and were a great deal then. The oiling fingers mentioned earlier are the oil baffles that are spot welded to the inside of the valve covers. They provided the same function as the rocker arm-mounted baffles in the '71/ 351C engines. The rocker arm baffles were not utilized in '70, so those one-year-only blue covers had the spot-welded valve cover baffles.

The '69-70 Boss 302 chrome covers also had spot-welded oil baffles and had slight differences in the shape around the oil cap area between the two years. This minute difference makes each year cover unique and worth $$$ to the serious Boss 302 parts collectors. The '70 style aluminum covers had the same oil baffle/fingers but were held in place with small screws and could be removed for use on a non-Boss engine. I discovered the interference Spike noted when I attempted to install a pair of aluminum covers on my '71 Mach 1.

The "Power By Ford" valve covers was used through early to mid '73 when a Ford oval-only version was phased in.

 The  illustrations are the '70 only blue cover, the under side of the chrome  Boss cover with the "fingers", and the  two different versions of the chrome '69 (left) and '70 Boss covers. That way, if you happen to see any of them while part scrounging, you'll know what they are!

6582-1970.jpg

6582-69,70B2.jpg

6582-69-70B2.jpg

 
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WOW this is great now reading this i went out in the garage and just staired at the motor with a whole new look ,,you see i bought this car for 1500 with no rust on the bottom thanks to Ford under coating and garage kept engine ran good,, put it in my garage and with 3 years of just picking at it and help from a friend lots of new parts and getting closer to restarting the engine again soon new dash,, carpet,,, head liner ,,,gas tank ,,traction action bars ,,new Air Ram Plenum under the hood  and more ..next might be LED rear lights the only change from stock all parts from CJ Pony ,, Q code numbers matching engine but some one in 1990 rebuilt the motor with 0.30 ,,0.10,,010 theirs a tag stuck to the bottom of the engine i do want to change the rear gears to 4.10 pos..

 

c9zx

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You bought the car in your signature picture for $1,500. If so, you got the deal of the century. Chuck

 

Kilgon

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You bought the car in your signature picture for $1,500. If so, you got the deal of the century. Chuck
He had attached a picture file in one of his above post.  Here it is.  Still a work in progress but looks like it's taking shape.  Looks good for price he paid.

thumbnail.jpeg

 
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