I heard you get bad piston slap with the standard sized forged pistons.
But until my wiseco's had bed in (about 130 miles) I experienced the same notsure.gif
I have noticed that the latest wiseco 8.9:1 pistons have a coating on the piston skirt, I assume to stop piston slap dunno..
my 11:1 cr pistons are actually quite old, the guy in Canada bought them several years ago and never fitted them, then I bought them from him.
I have since discovered that z22yh pistons are almost identical to my 11:1 cr pistons, they even have the coating on the sides, the only difference being they don't have the valve pockets machined into the crowns, but thats an easy job for a machine shop.
What about using saab turbo pistons or vectra z20net, they won't need a rebore
they cost about £120-150 each, but come with rings