Who was that Jon , was the frs head modified i.e. oversized valves , custom cams etc.
Oh and Luca engine was 533bhp and Stuart meads mini I think that was around 600/650 bhp but it was using either 100/150 shot of nos.
I don't think the blocks are a problem , it's the heads . The black top and silver tops are very similar in terms of power ( so far proven) it's only custom heads and the st170 head that has gone past the 650 bhp mark. I know will gallops focus rallycross car was one of the best specced zetecs out there and one of the first as well and used in competitive motorsports , it had 10inch runners on the inlet manifold which was then mated to an rs 200 plenum which we all know can do massive numbers in standard form. Anyone knows you could easily get 650 bhp out of a zetec by banging massive boost through it but it's just a question of how long it lasts , weather your going to have head lift etc.
That's why iam looking into wire ringing the block and going larger proper head bolts , I want a reliable , safeish boosted engine and not a time bomb.
P Johnson engine was reliable broke records
Lucas engine did the same
Stuart meeds mini did the same
Iam just interested to see who's pushed it that little bit further on and if or what issues have they had with there spec ( apart from oil pump issues)

Cheers paul