Those wheel requires 235/35 and 265/30.
I sold 3.0si to a previous owner of M3 and he put his CSL wheels to 3.0si - he is not lowered with stock suspension and is fine. Rear is REALLY aggresive.
I don’t think this would work without chopping liners on the rear, playing with geometry and really stretching the rear tyres as the concave on the rear wheel is so deep.
I managed to stuff 19 x 9.5 et 33’s on the rear of mine with a 255/30/19 tyre on eibach pro kit springs.
I then had to get the rear re aligned slightly as the rubber was catching on the liner. I definitely wouldn’t have been able to get 27’s on mine.
Good luck if you go for it but it would be a case of making them fit imo