I mean I need to ask my mates.

I think those 170 HP could be enough for me, because 2nd stage planned to tune zetec to n/a 150-160 HP - I'd like to use my Fiesta as everyday car. But I'm thinking about the example you gave (flywheel and clutch), so I need to compare money needed to insert zetec and tune it, and costs of putting in duratec and potential costs of repairs: 146HP (almost 150HP would be enough for me, I know how mk3's run with N7A) or engine from Focus ST.