The answer is to drop in an asian market 4Y. Straight in. Use a Weber carb from Oz and you can jet to suit. Weber comes with a Lynx air filter, fuel line, vacuum line and a wire for the electric choke. That's all.
2Y is 79 hp @ 5000 rpm and 140 nm @3200 whereas 4Y is 95 hp @4400 and 182 nm @3000 Gear up with slightly taller profile tyres. I run 205x60x15x6.5 alloys from a Daihatsu suv.
More power and huge increase in torque at around same revs. Result it pulls hard everywhere and with the zero emission control junk sensible fuel economy is restored.