Which B&S engines will fit Husqvarna YTH20K46?

[40bes249]

Can I replace an I/C 17.5 HP 500cc B&S engine 31C707 0230 E1 030609ZE in my Husqvarna YTH2046 with a B&S vertical 17.5 HP 500cc INTEH engine 31R977-0054?

 

[StarTech]

On that mower I would go ahead and upgrade to a 21 hp 330000 series engine as the YTH20K46 should had a 20 hp to start with.