Lost with my bbc id !

[French]

Merry christmas ! I 'm lost with my engine Id
-The block casting is 3963512 , it's mean a '69 427 or a '70 454
-On the front pad TI1I7CGV , CGV means '70 454 right ?
- But near the block casting # i can see a big GM 8 : Does it mean 1968 ?
How to see the difference between a 427 and a 454 ?
Can't remember my heads casting but I think they come from a 396 ci

What do you think ? thanks

[bruceman1968]

French, Your casting number 3963512 decodes as 427/454, 69-71, 335-450HP
Your engine stamp suffix code CGV decodes as 1970 454, 345hp, 400trans, LS-4, 4bbl, impala

[geezer#99]

Put this in your favourites folder on your computer. It will come in handy.
http://www.nastyz28.com/decode.php

[prostreetC-10]

When your block hasn't been decked and you still have the PAD numbers, they are all that matters. It's kind of like a 14x7 rally wheel. Came on a bunch of cars but it's the 2 digit letter code by the valve stem that will tell you EXACTLY what it cam on. 427 and 454s share the same bore. It's just the crank stroke that makes the difference. Therefore GM used certain blocks for many different cars/trucks.

[French]

Ok , but do you have an Idea about the big GM-8 stamped near the casting #

[Ol Blue K20]

Also 427 is internal balanced 454 external balance, 454 flywheel/flexplate and Harmonic balancer have counterbalance weights 427 doesn't

[bruceman1968]

French, I'm not 100% sure but I think that is a mold number. It could also be used for quality control by measuring the height of it.
I am sure that it doesn't tell anything about the size or application of the engine.

[French]

Thanks a lot !

[prostreetC-10]

Originally Posted by French

Ok , but do you have an Idea about the big GM-8 stamped near the casting #

I'm sure it has some very general meaning but really means nothing since you have the other 2. Might be a GM plant ID.