ragtopz28

iTrader: (57)

I know there is a ton of threads on this and in my quick search saw conflicting information. Block # is 12559378. I've seen 2000-2002, 2001-2002, 1999-2000. The motor is supposedly a GM replacement in 2004 (into a 2000 Formula). The motor does have 241 heads, no intake, and 12559287 stamped on the rear cover.
Any way to confirm exact year? I am only interested in it if it is a 2001+

Thanks as always.

dr_whigham

iTrader: (49)

The way I always cared:

Does it have ridges under the valley cover or not?

If it has ridges... Lines, then it's an older LS1.

If it's smooth inside, then it's newer. That's all the help I can give you

ragtopz28

iTrader: (57)

Thanks Dr. W....anybody got anything else??