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Old Feb 9, 2008 | 07:40 AM
  #1  
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D.T.
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Default Engine Serial Numbers

My folks have a 1969 convertible. The problem is the engine numbers do not match. Engine is supposed to be the 350/350 setup.

Here are the numbers we found on the block.

TO 0625HN

18J302353

82396124

We figured out part of it, like the first few. June 25 Topeka. All I could figure out on the second is 1 = GM, 8 = 1968 J = ?

What does the rest mean? What do the 350 HP motor numbers look like? We thought it was a 327 C.I. motor.

Last edited by D.T.; Feb 9, 2008 at 08:23 AM.
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Old Feb 10, 2008 | 01:59 PM
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DT,
I've tried to find some info about your engine numbers without any luck.
I don't see any 68-69 Corvette suffix listed as HN. The only HN suffix I can find is for a 1965, 327, L84 engine. That was the 375 horse FI engine. As for the block casting numbers all 68-69 engine numbers were 7 digits, all beginning with 39..... .The number for the 65 HN block would be 3782870. That's all I know, sorry.
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Alan
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Old Feb 10, 2008 | 03:14 PM
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My NCRS book says the 69 350/350 should be a 3927187 casting. cant find a J code except for assembly plant which would be Janesville. maybe you could find out what kind of cars were made there?

wait, thats the intake manifold casting number. Block could be either 3932386 or 3956618, then it says "late small blocks" 3970010, but no HP designation.

Last edited by 454_71Stingray; Feb 10, 2008 at 03:18 PM.
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Old Feb 10, 2008 | 03:31 PM
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Maybe '68 Full Size (Impala) 327/250 AT

-Mark.
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