Will it fit? I want to fit a solid flywheel with clutch on my st170 but the aftermarket kits cost a fortune so was wondering if it was possible to fit the 2.0L Zetec one as they are pennies when compared

 

several probs with that route, best you have a look on this thread about mtx 75 conversion the cars came with 2 different sized f/wheels, up to 2003 mid 230 and then 240 post that time, also getrag does not have same spline pattern, nor is the 2.0 std s/mass same depth as the st's D/mass f/wheel , the clutch needs to be sprung if S/mass unit is used.. see here for a decent look at whats needed..
https://passionford.com/forum/restor...onversion.html