Engine block ID
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Intermediate
Joined: Mar 2015
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Engine block ID
I stumbled across a 1971 454 Corvette. The engine has P/N 3963512. I did some research and I found the engine can be 427 for a 1969 or the engine can be a 454 from 1970-1976. The manufacturing alpha/numeric is I-18-9 (September 18, 1969). First, is it possible this engine could have been put in a 1971 Corvette at the factory? Second, how could I determine the correct size of the engine?
Team Owner
Joined: Sep 2006
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From: Westminster Maryland
Hi b,
The 3963512 casting number was used for both 427 and 454 blocks.
A block with an I 18 69 casting date would not typically have been used in a 71 model car.
Is there a chance its a' 0' rather than a '9' ?
What is the stamped information on the 'pad' in front of the right side head?
There should be 2 stamps… one describing when and in what configuration the engine was assembled, and the other indicating what vehicle it was first installed in.
Regards,
Alan
This is a sb pad but the bb pad is in the same relative location.
The 3963512 casting number was used for both 427 and 454 blocks.
A block with an I 18 69 casting date would not typically have been used in a 71 model car.
Is there a chance its a' 0' rather than a '9' ?
What is the stamped information on the 'pad' in front of the right side head?
There should be 2 stamps… one describing when and in what configuration the engine was assembled, and the other indicating what vehicle it was first installed in.
Regards,
Alan
This is a sb pad but the bb pad is in the same relative location.
Last edited by Alan 71; May 22, 2017 at 09:26 AM.
Thread Starter
Intermediate
Joined: Mar 2015
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Here's the poop. I spotted a 1971 (haven't seen yet-only photos) a supposed LS6. The first thing I looked at was the tach because of the red line difference between the LS5 and LS6. Sure enough, its an LS6 tach. The air cleaner has the 454/425 HP sticker on there. I realize anyone can put that on there. The info I mentioned about the engine is what has been passed along to me. I'm waiting for more photos to clearly ID the engine. Anyone have any other very direct facts on identifying a LS6 from LS5 pass it along to me please. Thanks
