Is this a 3963512 casting?

DavidS · #1 02-06-2010, 02:26 AM

I recently bought an engine that is supposed to have a 3963512 casting #.

I can make out 39?3512 with a sideways P below.

The 512 is very clear. Are there any other GM big block engines ending in 512????

I searched like crazy on the web, but could not find any. The third digit in is a mess. I gently scraped some of the paint off, but I still have no idea what number it is.

Here is a picture:

This is a pic of the area above the casting number:

Is the date code is supposed to be here?

Any help would be greatly appreciated!!!!!

David

**iluv69s** · #2 02-06-2010, 03:11 AM

check down on the side of the block for a date code...

DavidS · #3 02-06-2010, 03:17 AM

Any chance you have a crude drawing or something showing where to look?

Thanks for the help!

XXXGoldL34M20 · #4 02-06-2010, 05:42 AM

yes,that is a 6.
they werent cast very clear as mine is the same,see attachment

is that a four bolt main block?

DavidS · #5 02-06-2010, 07:27 AM

GREAT!!! You are right, the 6 is not clear at all and it does look the same. Yes it is a four bolt main.

Thanks,
David

DavidS · #6 02-06-2010, 07:28 AM

XXXBlackLs6M22,

I forgot to ask. Can you show me a picture of where your date code is?

David

**69 Post Sedan** · #7 02-06-2010, 05:06 PM

[ QUOTE ]
Any chance you have a crude drawing or something showing where to look?

Thanks for the help!

[/ QUOTE ]

Here are a couple of pics from a 1969 427 cast A.27.9. It's on the passenger side of the block. The 9 is tough to read.

Hope this helps, Kurt

**bergy** · #8 02-06-2010, 05:38 PM

Yeah - Fall of '68 through about March of '69 the date was cast on the lower side. It was moved to the upper flange because of the problems wth sand sticking to the pattern on the lower (drag) side. Pattern release spray would puddle on the date charactors on the drag and cause the sand to stick to the pattern. The upper flange location for the date tag was machined into the patterns, but not used until all of the patterns were converted. Thus, you will find the upper tag location with a "blank" tag in it (not ligible)on transition castings. The big blocks were all cast on line #1 and my recollection is that there were 4 sets of mold line patterns for 512 blocks.

XXXGoldL34M20 · #9 02-06-2010, 05:39 PM

[ QUOTE ]
XXXBlackLs6M22,

I forgot to ask. Can you show me a picture of where your date code is?

David

[/ QUOTE ]

my date is on the oppisite side of the block.
see attachment.

**61 vert** · #10 02-06-2010, 07:14 PM

DavidS. Sent you a PM.

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