I have a d15b7 block I am building for a mini-me setup, I have sohc zc pistons I'm gonna use in it (PM6) the block has pm3's in it now. I noticed that the pm6 pistons are slightly recessed and the pm3's are completely flat, except for the valve reliefs. I thought that the zc pistons were a high compression ratio, or is that just on the DOHC zc. If not, then using them will actually lower compression slightly. anyone have any info about this.

 

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