Physically they will bolt up in place of your original 1.0 clocks (assuming you're fitting mk1 clocks to a mk1 or mk2 clocks to a mk2 obviously!) The 1.0 speedo cable and the wiring will connect up to the turbo speedo, though I'm not sure that the speedo will read correctly and you'll also have some redundant gauges (oil pressure, oil temperature and tachometer). Oil pressure and temperature won't work unless you fit the relevant sensors to the engine. The tachometer is easy to sort out requiring only one additional wire from the LT side of the coil to make it work.
A few members here have fitted turbo (and SX) clocks to lesser models so they should be able to guide you. There is also a guide by Louie Bee on wiring up the tachometer - I'll have a search and post it for you.