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Need some help decoding this 327. Some people on a facebook group have differing opinions on what's going on with this block. The engine id stamp is crooked and runs off the pad, but also doesn't have the vin or serial in front of it. Thanks in advance!
The NCRS Spec Guide shows the ...174 block as used in '66 for 300 and 350 HP 327s, but I believe its use in Corvettes was very limited. The 350 HP (L-79) engine was also available in Chevelles and Novas, maybe 300 HP too. I'm not sure., but this may be the reason for no VIN derivative stamping. I'm not sure if the A and X body plants stamped a VIN derivative.
The C96 block casting date code is March 9, 1966.
I'm not sure if ...174 blocks were cast in Flint, Tonawanda, or both, but the engine was assembled at Flint on what appears to be March 11 (The II meaning 11) , and given that's only two days after the block casting date, it must be a Flint block. The last character is most likely a T, not I, and the HT suffix was for the 350 HP L-79 engine with manual transmission. The Spec Guide does not list a HI code, but it only covers Corvettes. It's possible there was a HI code for L-79s installed in other Chevrolet models other than Corvette.
The NCRS Spec Guide shows the ...174 block as used in '66 for 300 and 350 HP 327s, but I believe its use in Corvettes was very limited. The 350 HP (L-79) engine was also available in Chevelles and Novas, maybe 300 HP too. I'm not sure., but this may be the reason for no VIN derivative stamping. I'm not sure if the A and X body plants stamped a VIN derivative.
The C96 block casting date code is March 9, 1966.
I'm not sure if ...174 blocks were cast in Flint, Tonawanda, or both, but the engine was assembled at Flint on what appears to be March 11 (The II meaning 11) , and given that's only two days after the block casting date, it must be a Flint block. The last character is most likely a T, not I, and the HT suffix was for the 350 HP L-79 engine with manual transmission. The Spec Guide does not list a HI code, but it only covers Corvettes. It's possible there was a HI code for L-79s installed in other Chevrolet models other than Corvette.
Duke
Duke,
If the last character is an "I" and not a "T", then it decodes as follows:
HI 65 327 250 4B,AC,MT CO
1965 327cu in/250 hp with 4 bbl carburetor, Air Conditioning and Manual Transmission in a Corvette.
The NCRS Spec Guide shows the ...174 block as used in '66 for 300 and 350 HP 327s, but I believe its use in Corvettes was very limited. The 350 HP (L-79) engine was also available in Chevelles and Novas, maybe 300 HP too. I'm not sure., but this may be the reason for no VIN derivative stamping. I'm not sure if the A and X body plants stamped a VIN derivative.
The C96 block casting date code is March 9, 1966.
I'm not sure if ...174 blocks were cast in Flint, Tonawanda, or both, but the engine was assembled at Flint on what appears to be March 11 (The II meaning 11) , and given that's only two days after the block casting date, it must be a Flint block. The last character is most likely a T, not I, and the HT suffix was for the 350 HP L-79 engine with manual transmission. The Spec Guide does not list a HI code, but it only covers Corvettes. It's possible there was a HI code for L-79s installed in other Chevrolet models other than Corvette.
Duke
Duke, don’t all 300+ HP blocks have a stamped VIN derivative? My theory was that this is a HI block. This was a 250HP 327 with the 3858174 casting number.
With block a block casting date of 3/9/66 and assembly date of 3/11/66, how could it be a '65 HI code 327/250? I suppose the same basic engine in other models would have different codes if different exhaust manifolds were used. I believe A bodies got different exhaust manifolds and X-bodies may have even used a unique L-79 block casting... something about the oil filter boss.
Like Boyan said this block looks like an original Flint broach and stamp pad. One clue is that the stamped engine code is so knarly. Worn die holder and dies worn to various degrees. Stamps that look "too good" are always suspicious.
If all the dies look new, my usual bet is that it's a restamp.
This engine was probably assembled on Monday and the operator was not feeling so good so the bottom of the last character fell off the pad.
With block a block casting date of 3/9/66 and assembly date of 3/11/66, how could it be a '65 HI code 327/250? I suppose the same basic engine in other models would have different codes if different exhaust manifolds were used. I believe A bodies got different exhaust manifolds and X-bodies may have even used a unique L-79 block casting... something about the oil filter boss.
Like Boyan said this block looks like an original Flint broach and stamp pad. One clue is that the stamped engine code is so knarly. Worn die holder and dies worn to various degrees. Stamps that look "too good" are always suspicious.
If all the dies look new, my usual bet is that it's a restamp.
This engine was probably assembled on Monday and the operator was not feeling so good so the bottom of the last character fell off the pad.
Duke
It can't...missed the casting date in the earlier post.
With block a block casting date of 3/9/66 and assembly date of 3/11/66, how could it be a '65 HI code 327/250? I suppose the same basic engine in other models would have different codes if different exhaust manifolds were used. I believe A bodies got different exhaust manifolds and X-bodies may have even used a unique L-79 block casting... something about the oil filter boss.
Like Boyan said this block looks like an original Flint broach and stamp pad. One clue is that the stamped engine code is so knarly. Worn die holder and dies worn to various degrees. Stamps that look "too good" are always suspicious.
If all the dies look new, my usual bet is that it's a restamp.
This engine was probably assembled on Monday and the operator was not feeling so good so the bottom of the last character fell off the pad.
Duke
I think that it is because this engine is not a Corvette engine. The variation in intake and exhaust is what drives the horsepower rating from GM. I have an HCH code '66 3858174 casting in my '64 roadster and that engine is rated for 275HP. It is a passenger car engine with no VIN derivative. But really there is no difference between that and a 327/300 Corvette engine other than intake and exhaust.
In short, my opinion is that this is an HI engine from a '66 passenger car. I think that there were indeed some '66 HI code engines and have seen some attestation to that. This information's reliability is highly variable.
With block a block casting date of 3/9/66 and assembly date of 3/11/66, how could it be a '65 HI code 327/250? I suppose the same basic engine in other models would have different codes if different exhaust manifolds were used. I believe A bodies got different exhaust manifolds and X-bodies may have even used a unique L-79 block casting... something about the oil filter boss.
Like Boyan said this block looks like an original Flint broach and stamp pad. One clue is that the stamped engine code is so knarly. Worn die holder and dies worn to various degrees. Stamps that look "too good" are always suspicious.
If all the dies look new, my usual bet is that it's a restamp.
This engine was probably assembled on Monday and the operator was not feeling so good so the bottom of the last character fell off the pad.
That is a perfect pad. Although not from a Corvette, it is beautiful. Please don’t deck or alter it.
Agreed. Someone on FB suggested that it is a HT engine from a Corvette with the VIN ground off. I could not understand how someone could reach that conclusion.
Agreed. Someone on FB suggested that it is a HT engine from a Corvette with the VIN ground off. I could not understand how someone could reach that conclusion.
So far, something that is missing from this discussion is that the Flint engine assembly plant did, in fact, produce real HT engines with no VIN stamping. Keep in mind that Flint applied the engine assembly code, but the VIN stamping was only applied when the engine was installed in a car going down the St. Louis assembly line.
Some of the engines assembled at Flint were sent to dealers and sold "over the counter" as complete engine assemblies. These engines never got a VIN stamping because they were never installed in a car on the St. Louis assembly line. They are, nevertheless, 100% genuine Flint engines.
I have one of these engines that was purchased as a "crate engine" in 1967, and I have the original receipt for the purchase. Below is a photo of the pad:
John Hinckley described to me the process at Flint that allowed such engines to appear. The assembly had to be a complete engine rather than a bare block or a short block. But, if it was a complete engine, it was diverted to the parts channel after receiving an engine assembly code stamping.
These engines are rare, but they are 100% legitimate products from the Flint engine plant.
So far, something that is missing from this discussion is that the Flint engine assembly plant did, in fact, produce real HT engines with no VIN stamping. Keep in mind that Flint applied the engine assembly code, but the VIN stamping was only applied when the engine was installed in a car going down the St. Louis assembly line.
Some of the engines assembled at Flint were sent to dealers and sold "over the counter" as complete engine assemblies. These engines never got a VIN stamping because they were never installed in a car on the St. Louis assembly line. They are, nevertheless, 100% genuine Flint engines.
I have one of these engines that was purchased as a "crate engine" in 1967, and I have the original receipt for the purchase. Below is a photo of the pad:
John Hinckley described to me the process at Flint that allowed such engines to appear. The assembly had to be a complete engine rather than a bare block or a short block. But, if it was a complete engine, it was diverted to the parts channel after receiving an engine assembly code stamping.
These engines are rare, but they are 100% legitimate products from the Flint engine plant.
I'm relatively new, learning as I go and am definitely not an expert. But this is great info and I love the story behind this block. I like that this engine stamp is authentic. To me, it fully illustrates the various baseline shifts (a graphic design term that describes vertical shift changes) and slight font size variations that are possible within a legitimate factory stamp. At first blush this stamp looks like the last three characters are running downhill, assumed to be impossible when using a gang. The smaller font size of especially the first "0," the perhaps slightly crooked "H" and the dropped "T" accentuate this illusion. But the stamp is in fact real.
The force exerted across the stamping isn't uniform. Which was a common occurrence. This one tends to be lighter in the left upper area. But the force on the right vertical of the H isn't as consistent. Note the metal forced up around the upper right vertical that isn't as visible elsewhere in the stamp. The upper part doesn't seem as one with the horizontal and possibly the lower part of the right vertical.
Why does the right end of the horizontal look like it has an end? While the left end is open or integral to the left vertical.
The force exerted across the stamping isn't uniform. Which was a common occurrence. This one tends to be lighter in the left upper area. But the force on the right vertical of the H isn't as consistent. Note the metal forced up around the upper right vertical that isn't as visible elsewhere in the stamp. The upper part doesn't seem as one with the horizontal and possibly the lower part of the right vertical.
Why does the right end of the horizontal look like it has an end? While the left end is open or integral to the left vertical.
Your thoughts?
This is well within the limits of normal factory variation on known-original pad stampings. There were lots of "H" inserts in a bin at Flint, and lots of gang holders. Some of these were old and worn, others less so. Many factory stampings have much more variation than this one.
327 decoding help
