Hi, I bought my GTO about 10 months ago, it had been sitting in a garage for 5 years, it’s been MOT’d had a new alternator, had to have the gearbox rebuilt and refurbished costing £1800, it’s an automatic non turbo but has AWD and the 4 wheel steering, is this normal or a bit different, I took it to a mechanic friend and he seemed to think this wasn’t normal but anyhow that isn’t my main query, I’m looking for advice on a garage in the North of the country that could carry out some upgrade/modification work on it, I want to have turbos fitted but can’t find a garage thats even able to consider doing it… It’s now become my daily driver so I want to invest some ££ into her to get her right, any help would be greatly appreciated, I live in the Lake District so a bit limited for specialist garages here… Cheers and Thanks Mark 
Welcome to the club mark,i live in the east mids so cant offer any advise in your neck of the woods all i can say it to convert an auto na to a tt is going to cost a skip load of money,probably be cheaper to jack it up and put a tt under it lol
It has been done in the past , more commonly on the N/a manual though , there have also been supercharged n/a’s
One of which is @jerry_SC car , I’m sure he can give you some advice and another option apart from turbos
Regards
Craig 
I read of one N/A that was converted to a TT, had to do the resistors on the injectors, do the Auto box with stronger components that were likely to fail, all the bits came from America, the problem with the N/A is the difference in the compression ratio. Hotter plugs had to be used and a myriad of other things. From what was said, the work taken, it would have been better just to buy a TT. Sorry to put a downer on it 
Terry 
Hello and welcome along to the club.