Bigger deck than what ?
Down here they came with a small deck ( 36" from memory ) to go through a standard Australian garden gate and the same 42" deck as the 300 series.
However it can only throw using the bigger deck because the engine is lacking the testicles to do heavier work like bagging or mulching.
The mounting points are the same but you run out of Hp very quickly so what you gain in the extra width , you loose by having to mow a lot slower & the inability to mow very tall grass full stop.