Just trying to gather as many specs as I can about this motor I purchased and was looking for some help.

Google hasn't really solidified my questioning.

Block Number: 12559378
Heads are 241
Intake: 12561184 (I understand this is the LS6 intake off an FBody)

I mainly curious about the year. Apparently there's enough of a different between the years to require separations for certain parts.

Thanks guys.

 

Your block is the 99-02 Aluminum 5.7 casting. Here is a site that lists all casting numbers with a description of the differences: http://www.enginebuildermag.com/Arti...all_Block.aspx