Difference between 88958602 and 19258602

[qwik83]

We are being allowed to run the 602 crate in out southern sportmods this season and we are allowed these 2 part numbers. I've looked at the specs of both and can't see any differences. Can someone help me out? pros and cons of each? Thanks!

[mqdirtracer57]

If I am not mistaken...the 19258602 is the newest part number that supersedes the previous 88958602. I seen a thread on here stating the new number has lighter pistons and better rings. It was posted by Chris Steele