If you wanted to build up a zetec engine to take a significant hike in power which would be the better block to start with? An earlier one from the likes of a mondy or escort or the later focus one?

And does anyone know the differences between them

I know the heads changed, with the hydraulic lifters being lost along the way, but was wondering what changed on the block like bearings, coolant passages or anything like that

Cheers dudes,

SPUD