(T) 1.2 8v and 16v

Hi everyone. I'm now thinking of putting in the 1.2 engine in my cinq Abarth. Apparently the 16v is a tight fit.
DO the 8v and 16v share the same block? If so, would the 16v head fit the 8v block?
Has anyone fitted the 16v? What problems did you come accross?
Thanks for you time.:D

p.s. Remember I was thinking of fittinh a supercharger. Turbotechnics are working on a compact 'charger. Check out this link www.Turbotechnics.com