Ok, I rebuilt my ls about 8 months ago due to all 4 ringlands cracking. Failure in the fuel system. lawl.

Motor's making a funny knock from about 3k-3300. I'ts not rod bearings. Thinking piston slap. Can I use stock bore 81mm pistons on new rebuild? I've got a set of low compression nippon pistons, just not sure if it will fix the problem.

 

Never mind. I found the search in the corner.

 

your better off going oversized pistons to make sure those cylinders are clear and get it honed