I need help choosing piston heads

I want to bore out my piston holes on my engine but I am not sure how big of pistons I can get without risking a cracked block or anything else. Could someone please tell me how big of a piston head I can get? My firebird has a 3.8 series 2 engine. A friend of mine told me that I could get it bored out from a 3.8 to about a 4.6, but that didn't hint to what size of piston head I could go with. Could I take my displacement up that much? Thanks a lot.

Mason

I don't think 4.6 is possible...

To find your max bore you would need to magnaflux the block. I wouldn't bore your engine out because it just isn't feasible. If you want to work ona 6 cylinder find some other mod to do, I think someone already has a topic about boosting a 3.8L's power.

http://www.automotiveforums.com/vbulletin/t133589.html

Or an engine swap for a LS1 Mmmmm.

I almost forgot, I think a 4" stroke and a 60 overbore gives you 4.6L, but I don't know if that is even possible.