Head numbering.

I called the helpful folks at LMC Truck to order a rebuild kit for the first real work on Green, the brake master cylinder, and found out it was nine weeks out on backorder.  So, rather than kill time I decided to hunt up some more numbers. The photos are a couple of weeks old, and this installment is being written up from Berkeley, California as I attend first the 50th California International Antiquarian Book Fair and then an academic conference on textbook affordability (plus getting a little research done at the Bancroft Library and some really good food between the two).

Like the component code found on the transmission casing and cover, the code atop the engine head on the driver’s (or manifold) side of the motor shows the GM for its origin at Saginaw Metal Castings Operation as one would expect, but I am puzzled by the “-26” that trails it.  The number just above that is pretty clear: 3836848.  I rather imagine that top number is a component number, because the Vehicle Information Sheet (VIS) clearly states that the engine serial number is “On crankcase at rear of distributor, on right side of engine.” That’s exactly where it is, so this cast number is certainly not the engine serial number. The only problem is that there is conflicting or badly composed information about just what numbers should be where.  One site states that the component casting number for the head on trucks of this year should be 3835409, and the Inliners site does not list the number at all.  I’ll keep looking.

On the opposite, passenger’s side of the engine head is another cast-in number, part of which is undoubtedly the casting date code–but I have not yet taken off the valve cover, which might reveal other numbers for the head.  If I am right that this number is the casting-date code, and if the code follows the pattern of the one on the transmission, “B58 848” and a zero on a line below and to the right would become B = February,  5 = 5th,  8 = 1948.  That is a bit odd because it suggests that the head was manufactured but then stored for a year, so I may be wrong. The other possibility is that someone forgot to change the year character.

Either way, you undoubtedly notice as I did that both numbers end in 848.  According to the helpful folks who run the Advance Design Trucks website, the “848” may be a code that identifies a high-compression head, but I don’t know which 848 it would be and don’t know how to find out.  Still don’t know what the 0 might mean, and I am not positive that I’ve read the numbers right, anyway.  I’ll tentatively call it . . . well, never mind; I’ll let it go at that.



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