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I looked again for a casting date code near the 3xxxxxx number, but can't find anything else visible there. Does anyone have a picture of where exactly I might look when the engine is in the car? I tried a search but couldn't come up w/anything.
Driver's side with block part number and pattern number:
Near top, driver's side still: I think that's the plant and shift clock and I'm not sure what the 3 is between the cast "screw heads"
And then here's on the passenger's side, the block cast date between the cast "screw heads" B252 which I believe is February 25th, 1972 for my March 13th 1972 coupe:
Someone please correct me if I'm wrong. So... 3970010 block from pattern 32 cast around 3pm during the 10am shift at the Tonawanda plant in Buffalo, NY on February 25th, 1972. I can't explain the cast 3 between screws near the shift clock casting.
In an article I read there were 12 conveyors. In the 2nd pic the 3 would signify it went down conveyor #3.
In the last pic because of one flat head and one round head it was made on the 2nd shift.
Interesting note on the conveyors, never knew that. Regarding shift, does that mean 2nd shift started at 10am?
Also, I realized I have no idea what the T G N symbol is, I thought it was which plant it was cast at, but if it was Tonawanda I'd think it'd be pointing to the T? I know up front is the stamp position for engine assembly plant, but I assume that's the plant where the engine is finished (in my case V for Flint, MI) and then mates to chassis, i.e., assembly so St. Louis (12Sxxxxxx) for a 72. But the block would have been cast in Tonawanda I'd think?
Interesting note on the conveyors, never knew that. Regarding shift, does that mean 2nd shift started at 10am?
Also, I realized I have no idea what the T G N symbol is, I thought it was which plant it was cast at, but if it was Tonawanda I'd think it'd be pointing to the T? I know up front is the stamp position for engine assembly plant, but I assume that's the plant where the engine is finished (in my case V for Flint, MI) and then mates to chassis, i.e., assembly so St. Louis (12Sxxxxxx) for a 72. But the block would have been cast in Tonawanda I'd think?
With very very few exceptions, all Corvette SBCs were cast and assembled at Flint. The casting date on this block has a single digit for the year which identifies it as a Flint block. Tonawanda used two digits for the year.
Ahh. So the block was cast AND built in Flint, then shipped to St. Louis for install. So any ideas what the TGN pointer casting is?
Don't mean to hijack DeadStang, just thought I'd post pictures that may help you locate your casting date as well as help in identifying more details on your block as well as mine!
The way alan71 once explain it was the TGN pointer designated which shift at the foundry cast the part. For example - daylight, twilight or night shift.
For many years the 010 and 020 numbers found under the timing cover on some blocks were mistakenly though to mean a high percentage of nickel and tin, making the block somehow 'better'. We now know that these numbers were the last three digits of the block casting number that the mold was used for 3970010 and 3970020 but the legend lives on.
I propose a new story that the TGN stands for Tin, Gold and Nickel. If anyone finds a block with the pointer at the G, it's made of pure gold and worth a million-squillion dollars.
Hi,
I agree about the D, T, and N indication, but I believe the pointer with the arrow and circle of dots wasn't indicating the time of day, (not 10 a.m.), but rather the hour count with-in the shift.
Regards,
Alan
Hi,
I agree about the D, T, and N indication, but I believe the pointer with the arrow and circle of dots wasn't indicating the time of day, (not 10 a.m.), but rather the hour count with-in the shift.
Regards,
Alan
Okay so the 32 is the pattern serial number, and a 3970010 block with pattern serial number 31? would have been cast at the same time with my 32 (Frank mentions pouring 2 at a time) from a mold number I don't know. As Frank put it, series XX patterns 31 and 32? Or perhaps it was incremental so pattern serial numbers 32 and 33 were in series XX. Not sure where Frank got the series (mold number) from.
As far as the clock goes, I just got that from nastyz28, but now that I re-read it that makes more sense. So it looks like my block was cast during the twilight or 2nd shift, 7 hours into the 10 hour shift. So if one knew when 2nd shift started, you could get the hour of day it was cast as well. No wonder searching Google for TGN was useless, it's apparently a D
qtlow's link was helpful, wish I had found that earlier!