Go to www.mortec.com
They have a page on site that tells you where to find your casting numbers, you can then look your engine up in thier casting number directory. It will tell you when the block was poured, when the engine was assembled, what vehicle the engine was put in when new and also tell if it is a four or two bolt main, what type of crankshaft and anything else special about it. You can also take your valve covers off and get your head casting numbers and find out all about your heads, valve sise, chamber sizes etc. This is a great site for finding out about an engine.