Should be ok as long as your chain is long enough to work with the bigger sprocket.
For street use I'd suggest a steel rear sprocket. Aluminum is a little lighter, but you'll notice your lighter wallet (they lasted around 5k on my 625SMC) more than the bike. http://www.drivesystemsusa.com/spro...0-pitch-black-steel-rear-sprocket-sku-14203r/ is a very lightweight steel sprocket, but not available in 43, only 38, 39, 41, 44. They're what I would run on my WR and YZ if they were available in the sizes I want, almost as light as aluminum and last way longer.