Stock GTE Pistons would also lower the compression ratio.
Here's what you do - if you want power - swap in another engine. 204hp is pretty much as far as you can go on a GE, which is what it puts out anyway.
Yes, theres a guy on here that has done a 3.5 N/A but that's taken insane amounts of money, from what i remember of his build.
For build - have a budget in mind. You have a horsepower figure in mind already. A 7M-GTE with BPU's would output 300hp. A 7M-GE would require massive investment for the same return.