Hector, I'd have to convert to mechanical lifters, valves and pistons.
I should have a Kent cam kit on the way from Burtonpower.
When I was sourcing a Zetec for this kit, I could not find a ZX3(focus), but I came across several ZX2 (escort).I was advised to stay away from the ZX2 becuse the waterpump is offset on the block. There is very little room towards the nose on a seven.
The Contour is the easiest Zetec to fit.