How do I tell the year and CID of my GM engine ?

[GulfCoastFighter0]

Sent: 7/4/2008

OK GM engine gurus, my Minnie Winnie originally came with a 400. The person I purchased it from said that he was told by the previous owner that he had the 400 replaced with a 350. The block is freshly painted, and new freeze plugs have been installed, so I'm sure the short block was replaced. The intake, and accessories look like they were used from the original engine. I can't find any numbers on the block, so I'm looking for guidance there for the year / CID for when I need parts. I'm pretty sure the plugs, wires, distributor cap and rotor will be the same between the two engines, is this true? Is the only real difference between the 350/400 the crank, rods or pistons?

[ZR91]

Sent: 7/4/2008

http://www.mortec.com/

This will help you decode your block casting #.
An easy way to tell is that the 400 block has one extra frost plug on each side of the block, and they are externally balanced as well.

Do a Google search, there are tons of websites with lots of pictures that show you how to tell the 400 apart from other GM small blocks.

Jay