im using the standard pistons and conrods in my 1.8 ZVH, and im going for about 200 BHP, i have had 30thou taken off the top of the pistons to reduce compression, And using the oil spray jets,

I am told this is fine and can run about 14 to 16 psi.

So i would of thought it would be ok in your zetec turbo. the only reason i haven`t uprated my pistons and con rods is due to cost, i dont have a grand to splash out on them, and want my car for show season this year, so maybe next winter i might have saved enough to change them so i never have to worry about them cracking etc.