HELP NEEDED: Intake Casting Numbers
Thread Starter
Instructor
Joined: Aug 2004
Posts: 124
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From: Highlands Ranch CO
HELP NEEDED: Intake Casting Numbers
I recently purchased a '68 BB. The engine code indicates it was once a 400HP car. I'm trying to determine what intake manifold I need. "Corvette by the Numbers" lists two casting numbers:
#3919850 (early)
#3937795 (late)
My question: When was the "late" manifold in use? Do I make a "best guess" based on the manifold's date code? Or, does someone have a more concrete answer? My car was built in early February.
Thanks in advance. I'm new to C3's and I'm loving the car!!!!
#3919850 (early)
#3937795 (late)
My question: When was the "late" manifold in use? Do I make a "best guess" based on the manifold's date code? Or, does someone have a more concrete answer? My car was built in early February.
Thanks in advance. I'm new to C3's and I'm loving the car!!!!
Instructor
Joined: May 2004
Posts: 200
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From: Weaverville NC Sit down, shut up, & hold on!
Im not for totally sure, but I believe that GM did everything after JAN 68 as Late You need a book (Corvette by the #s ) or someone with NCRS, I know I need the book and join NCRS. From one BB 68er to another. Good luck w/ the Vette 
Burning Brakes
Joined: Aug 2004
Posts: 856
Likes: 2
From: Tyler Texas
Casting numbers for all 68-69 aluminum manifolds are on the underside and therefore not visible when manifold is installed on engine. You are correct re the two manifold numbers for 1968 code IM/IO 427/400 engines. I do not know when the "late" changeover date occurred. I am sure someone on here does though.
Melting Slicks
Joined: Jun 2001
Posts: 2,340
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From: Moro IL
Originally Posted by Patrick73
Casting numbers for all 68-69 aluminum manifolds are on the underside and therefore not visible when manifold is installed on engine.
Pat Kunz
Thread Starter
Instructor
Joined: Aug 2004
Posts: 124
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From: Highlands Ranch CO
Thanks for the feedback. Today I was told that the NCRS Pocket Spec Guide indicates that the change took place in March. Looks like I'll need the earlier one. Luckily that's the one I've recently come across...
Burning Brakes
Joined: Aug 2004
Posts: 856
Likes: 2
From: Tyler Texas
Clarification: Casting DATES for big block alum. intake manifolds are on the underside and can not be seen. (for cast iron manifolds they are on top).
Casting NUMBERS for all 68-69 intake manifolds (both big and small block) are on the top surface and are visible when installed.
I should have been more clear in my earlier posting.
Casting NUMBERS for all 68-69 intake manifolds (both big and small block) are on the top surface and are visible when installed.
I should have been more clear in my earlier posting.
