I'm In The Middle Of The Rebuild On My 01z.

My First Question Is What Is The Highest Compression Ratio That You Can Run On Pump Gas. I Know That The Stock #10.5-1
Is Very Close To The Edge.

My Next Question Is If Any One Has Ever Used Diamond Pistons.
I Am Looking At The Dome Tops But I Think We Are Getting To Close To The Edge. There Dome Top Is A 11.5-1 Ratio Out Of The Box.

 

I can't give you a complete answer but I am rsearching after market heads and it seems like they all bump the compression up to 11 to 11.25 depending on if you want to fly cut the pistons.