I just picked up a bare ls1 block. From looking at it I know its a 97-early 99. I can tell from the oil passage on the back. Here's the kicker, the casting number came up as a 97. The guy I got it from pulled it out of his 99 and I haven't been able to get a match on the serial number on the back. I'm assuming its a partial vin.

I've been looking into it and have come across opinions on the 99 blocks. Some can be honed slightly more (.010 compared to .004) and that the oiling set up can be improved with a little port work. I haven't really found a definitive "this is what it is and how to fix it" type resource.

Where can I find a decoder for the serial number?
What exactly can be done to help the oiling?

I'd like to build the bottom end may even stroke it. The original goal was 500 to the ground stock cube and then throw nitrous at it, 150 shot minimum.

Here's the casting number and serial
12550592
9802909102(first # could either be 8 or 9, hard to make out)

 

here??
https://www.google.com/search?q=GM+b...ient=firefox-a