OK, going to get a stroker rotating assy. and they talk about flat and dish pistons. I just have stock heads that have been ported by a professional shop (very good work and thorough BTW).

I have no idea what the cc's of my heads are so no idea what to get. I can only get 91 octane here in Phoenix. Going to stay NA.

Also, what overbore is standard? I want to leave room for myself in case I ever have to rebore one more time.

Ben

 

talk to the people your ordering it from, sure they know a good bit

 

Most people going N/A get about a 5cc dish on their pistons. Sometimes they're flat tops with a valve relief that equates to 5cc. This will reduce your compression a little. If your heads have large chambers, you may want a domed piston, but if they're milled too much, you could have too little piston-to-valve clearance. If it's not that big of a deal, just get the 5cc dishes and call it a day. If you really want to know your compression, find out more about your heads. LT1 owners usually get a .030 overbore and rarely any more than that unless by accident. The returns are pretty diminishing after that and the cylinder walls aren't that thick from what I understand.

 

You need to get your chambers cc'd in order to at least have one tool to calculate an accurate compression ratio. You also need to figure out if you want your block decked and what thickness you will use on your head gaskets. Your shop should know this. No offense, but you need to build a relationship with the shop you are using. You need to talk to them about these things.
Even if you had 93 octaine living in a high altitude area it may hinder you more than help.
.030 is standard.

 

no
yes

 

CC the heads yourself, then you will really know. Piece of plexi over the chamber, filled with oil from a syringe. Pics and process can be found here. That info, plus your desired compression ratio, will help you pick the right head gasket and pistons.