Well, kabli engines are not 100 % guaranteed to perform you know... However, most shops have a weeks checking warranty so it will not be much of a problem... You need time and patience... A very very good electrician and a trusted and skilled mechanic...
These cars are full of electronics and sensors so a single fault, may it be a short wire, will cause exponential problems...
Ask around, talk to people who may have done this swap... I was about to swap my car but stopped after i realized what I was about to put myself into...
Cheers...