The BME 50 is an excellent engine, Spitfires however by their design have long narrow cowls so engines with side mounted carbs usually end up with the carb or it's intake partially sticking through a hole in the cowl, which is not a problem, just undesireable from a scale point of view. Engines with rear or front mounted carbs like DA or MVVS usually make for a much cleaner install.

Karol