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"There are several notations about crankshafts ..... notes that cranks balanced for the 4 inch bore have a "4" stamped onto a milled surface ..."

Does the SC actually use the word "balanced" ???

Is there a difference in the piston skirt or overall piston height between 320 and 352 and 374 that is NOT a function of diameter????

What i'm getting at is that the crank difference between one stamped "4" and another stamped "3" mite be for piston/counterweight clearence and NOT balance.

Thanks for the info. The one clean crank I have on hand has a 4 and a B stamped back to back, meaning one is upside down to the other. I believe this crank came from a 374". Any ideas as to what the B correlates?

I have one reliable sighting of 320" forged cranks and supposedly, they had smaller counterweights than did the 352". Randy, did you notice any physical differences between your forging and castings? Obviously, with solid crankpins, it should weigh more than the 56# of the cast crank with hollow crankpins. The solid pins would add several ounces to the rotating weight, so the counterweights should have to be larger to compensate. If anyone ever has one out of a car, weigh it! On second thought, I know where there are a couple. I'll see if I can get one weighed by phone.

thnx, jack vines

I believe i have a 320 head. Maybe 2wo heads of unkown origin. It's real ez to get to but i'll have to look at it later on tonite.

Yes, PackardV8, it did use the word "balanced". Do you not have a set of Service Counselors?

Gentlemen, this is the document you seek (link to complete document pdf):

packardinfo.com/xoops/html/downloads/SC/SC-VOL29NO7.pdf

As Brian said, stay tuned as his excellent research is coming together with my "web-kung-fu" to bring you a very easy new feature for the website to help find, and access these types of service documents.

Attach file:

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I do not have 55 SC's. Only 56's. I'll download the 55's later on.

I have cyl. head 440689 cast on the exh. port. Dated 5 27 55 on top deck of head under valve cover. A "3" is also cast just above the date. The head is real cruddy but appears to be original paint and is either white or Ivory. I have the mate to it too but have not checked it yet for numbers. History of heads UNknown.


I checked 3hree of my cranks. NONE have any "4" nor "3" on the front weoght that i can see. All 3 cranks have a "TT" STAMPED on the machined flat of the front counter weight. One has an "E" on the machined flat of the opposite side of the front weight and a dab of either white, lite beige or iviry paint on the front counter weight.. So these would all be 56 cranks???

Pics on request. One of the cranks is from 5672A 1834 with engine number AND vin stamped at the front by the oil filler.

Also note:

Insert Main bearing material is different for ONLY the 320 front 4 mains. See service manual 55 and 56 engine specs at the rear of the book for details.

Would this raise any suspicion that maybe the 320 crank was cast of different material from all other PAcKard V8's????

"Then there is a subsequent notation relating to the first that says the crankshaft with the #4 stamped may be used for either the 4 or 3-13/16 engine, but those with the #3 can only be used on the 3-13/16 engine."

This COULD very possibly mean PISTON to C'Weight clearence or some other clearence issue.

Between my two 320's, I have both the cast dome and the machined versions. I'll have to check tonight to see which one's are on my Patrician, but if I remember right, it's the machined ones. I also have a crankshaft that's out of my parts 320 that's been machined already, I can also post a pic and note the #'s that's on it. BTW, I also have the 374 that came out of my Patrician at the house, I can look for #'s on that crank too, but since it's stuck, it may be on the "back" side of the crank and I won't be able to see them, no promises there.

I also have a connecting rod from my parts 320, I'll post the part # from it, too.

BTW Owen. I just found the 55 SC's. They were right there with the 56's all along. The index for the 55 and 56 SC's indicates only "Page 36" for any reference to the "3" vs "4" cranks. I'll look further thru them.