69 M code engine block

Reply Subscribe

Thread Tools

Search this Thread

Feb 16, 2013 | 09:04 AM

JimE

Thread Starter

Burning Brakes

Joined: Apr 1999

Posts: 861

Likes: 9

From: Summerville SC

69 M code engine block

Are there any members out there, that own a 69 with an M code block instead of a casting date?

Feb 18, 2013 | 12:09 PM

MelWff

Race Director

Joined: May 2006

Posts: 18,731

Likes: 2,582

Where on the block are you looking? Small block or big block?

Feb 18, 2013 | 12:24 PM

restoman1

Burning Brakes

Joined: Dec 2010

Posts: 848

Likes: 60

From: CA

Jim, in the first generation Camaro world we run into this periodically. Research by the Saginaw Metal Casting Operations of GM Powertrain Division has found that these "M" codes are not date codes, but actually a foundry code used to indentify parts that were made to evaluate a casting process change. After evaluating the parts, the blocks would either be destroyed or released into production. There is no way to determine the date an "M"-coded block was poured.

Ed

Feb 18, 2013 | 06:24 PM

JimE

Thread Starter

Burning Brakes

Joined: Apr 1999

Posts: 861

Likes: 9

From: Summerville SC

Thanks for your response. Is there anyway of knowing how many of these blocks were actually used in production for 1969. The couple of 69 vettes I have seen seem to have early build dates, Oct 68 body build C--.

Any other input greatly appreciated.

Thanks