cylinder head casting dates
Thread Starter
Melting Slicks
Joined: Mar 2004
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cylinder head casting dates
What is the legitimate range of days between the casting date of an engine block and that of the heads to support originality?
For instance, if the block has a casting date of I305, how far back can the casting date of the heads be before one has to doubt that these are the original heads?
For instance, if the block has a casting date of I305, how far back can the casting date of the heads be before one has to doubt that these are the original heads?
Team Owner
Joined: Oct 2000
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From: Washington Michigan
Typically, the heads and block dates were within a week or two of each other during normal production, but from an NCRS judging perspective, any block casting date up to six months prior to the car's final assembly date is OK; head casting dates aren't judged - only the external configuration and casting symbol on the end of the heads. Of course, the block casting date must precede the engine assembly date stamped on the pad.
Another thing to remember is that Tonawanda heads (which were never used on SB Corvettes) can be spotted externally (without looking for the two-digit year portion of the casting date under the valve cover) by looking at the ends of the head; The casting symbols on Tonawanda heads are as-cast on the ends, and the symbols on Flint heads are machined with a flat face.
Another thing to remember is that Tonawanda heads (which were never used on SB Corvettes) can be spotted externally (without looking for the two-digit year portion of the casting date under the valve cover) by looking at the ends of the head; The casting symbols on Tonawanda heads are as-cast on the ends, and the symbols on Flint heads are machined with a flat face.
Melting Slicks
Joined: Jul 2004
Posts: 3,490
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From: Kissimme now from LI,NY
What about
Originally Posted by JohnZ
Typically, the heads and block dates were within a week or two of each other during normal production, but from an NCRS judging perspective, any block casting date up to six months prior to the car's final assembly date is OK; head casting dates aren't judged - only the external configuration and casting symbol on the end of the heads. Of course, the block casting date must precede the engine assembly date stamped on the pad.
Another thing to remember is that Tonawanda heads (which were never used on SB Corvettes) can be spotted externally (without looking for the two-digit year portion of the casting date under the valve cover) by looking at the ends of the head; The casting symbols on Tonawanda heads are as-cast on the ends, and the symbols on Flint heads are machined with a flat face.
Another thing to remember is that Tonawanda heads (which were never used on SB Corvettes) can be spotted externally (without looking for the two-digit year portion of the casting date under the valve cover) by looking at the ends of the head; The casting symbols on Tonawanda heads are as-cast on the ends, and the symbols on Flint heads are machined with a flat face.
John,
Not to hijack this thread, but i was reading in the Nolands book that the "180" block (for a 65) was seen to be up to 9 months off of the build date. Is this truly the case or has that changed due to new information.. Especially since I have one that is 7 months off the build date... :-)
Thanks,
/joe
Team Owner
Joined: Oct 2000
Posts: 38,897
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From: Washington Michigan
Originally Posted by joec
John,
Not to hijack this thread, but i was reading in the Nolands book that the "180" block (for a 65) was seen to be up to 9 months off of the build date. Is this truly the case or has that changed due to new information.. Especially since I have one that is 7 months off the build date... :-)
Thanks,
/joe
