Originally Posted by Jazer

Cracked ringlands on #1 would be my guess.

Fix it sooner than later... Mine had cracked ringlands on the #4 (and #3 minimally).. ran like that for almost a year (X didn't realize how bad the blow by really was), that, and he didnt care cause he wanted to rebuild it anyways. When we pulled the motor out and got around to rebuilding it, saw that the blowby steam cut the cylinder wall over time and melted that area of the piston. Don't want to have to resleave your block on top of it.

GM's build book has some good info on installing pistons. I used the GM build guide (to 300) + Haynes manual + Alldata, as a refrence when I rebuilt my LSJ. All contain torque specs and some step by step instructions in case you happen to need that.