Can forged pistons be milled to lower compression?
 

I know that with a 350 the lower compression slugs are so cheap, machining doesn't make sense but I was on an import site where they were talking about dropping the compression on an M3 Roadster to s/c it and the blower pistions were over $100 each. Generally speaking, is there any reason why you can't mill the dome off a high compression piston, especially if it is forged?

I suppose it could be done. I wouldnt want to for fear Id mess up teh valve reliefs or something

GM used 11:1 pistons in the early 70's, when they wanted to run 10:1 compression pistons in the Camaros, rather then redesign a new piston theys imply took the 11:1 piston, and milled the dome off. So yes, I would think it could be done.

You sure they didnt just increase the combustion chamber size a bit?

Yes, you can mill them down. My brother is having his LT1 rebuilt and we got a set of forged pistons from a friend of ours but they were 10.5:1 with a 64cc head and the LT1 has a 58cc head so they are being milled down so it will be 11:1 with 58cc.
Should get it all back this week and put in by the weekend, hopefully.