[crazymechanic]

~8.9:1 with SVT gasket

~9.2:1 with Zetec gasket

I don't think it'll be that low...zx3 and svt heads have similar combustion chamber volumes, the increased compression on the svt is due primarily to the pistons, so it'll be closer to 10:1 unless you change the pistons out

 

[crazymechanic]

it would jump maybe .2-.3 tops

 

[crazymechanic]

I think that's a bit of a stretch...the head gasket isn't THAT much thicker