Hi GMS, I am the tech guy on the impalas.net site and am 1/3rd of the impala database.
The 0460 is some kind of internal plant code probably for tracking the car on the assembly line. It is referred to on your build sheet as "B RUN" in box 107. The car with the vin consecutive to yours would most likely have a consecutive B RUN number. Could you send me a picture of the build sheet for reference? My email is Tranenut@juno.com
Sounds like a neat car and its great to find the build sheet. If you keep looking, you will probably find build sheets up under the hood insulation and under the front and back rear seats and in the back of the back seat. There may be one in the back of the front seat but I would only look in there if you were going to redo the seats. You may even find a build sheet from a car build just before yours.
I have a lot of experience with Wilmington, DE cars.
Warren
Hi Warren,
Since this thread is sort of old I don't feel too horribly about high jacking it...It is a long story but the long and short of it is that a good friend of mine is trying to help the widow of his best friend decide what to do with the departed's '66 Impala. I would like your input on the numbers form this car. I am going to post the photos and data here so as to take advantage of the collective knowledge on this site.
Here is what I have so far:

Which I break down as follows:
16837 = 2 door sport coupe, Impala SS V-8
6 = 1966
C = Southgate CA

02C = Built third week of February
66-16837 = 1966 Impala SS, V-8
BC = Southgate, CA plant
7829 = Internal scheduling/reference ??
813 = Black interior
KK = Mediaum Turquoise/Artesian Turquoise paint
C60 = AC

3855961 = 65-66 passenger 396 CID, 325 HP 2-bolt block, also 66 Chevelle 396 CID 325, 360 HP, 2-bolt block

TIII7IN = Tonawanda, November 17 ... Suffix = 1966 passenger 396CID 325 HP TH w/ A.I.R.
The next stamping seems very odd...but to me it looks as if the block carries factory broach marks. The TH-400 is still on the car haven't pulled any numbers from it.
So, does this engine seem like the "born with" power plant for this car?
Should the car have a 12 bolt or 10 bolt? (curently has 10 - bolt (based upon rear cover config)
the car has a decent interior and is fairly straight although now in white. Engine compartment is messy and th most of the AC is gone (firewall suitcase is extant as are the internal controls but everything else is gone)
Can you give me a ball park figure on valuation on such a car? I am trying to help my friend help the widow and her children - honest. they are hoping to cover funeral costs and then some with the sale of the car.
any insight appreciated - from anyone
I'll drop an email as well,
thanks