Sure there is. The sky is the limit, but assuming you want to keep the sled trail friendly and reliable I would suggest the following.
Spx single pipe + 4-5 hp saves 5 lbs $ 399.00 comes ceramic coated.
Spx Hyper shift clutch kit $ 130.00
10.4 secondary clutch kit upgrade $ 295.00 offers even better bottom end and response over the hyper shift kit.
Spx timing key adds 2-3 hp $ 21.00
Spx high flow intake adds 2-3 hp $ 77.95
All of these upgrades are 100 % trail safe, but you need to run premium pump gas 100 % of the time.
No fuel controller needed.
If you are looking for more let us know. This is what we consider our stage 1 kit.