If you are using a hotter plug than the OS 8 in your Evolution .46NT, then it will have more power than the .46FX. You can see the difference by using an A3 plug and retuning your Evo.

Both engines gain a significant bit of power with the Tower's muffler.

If that .46FX is in good shape, it may be a good idea to use some castor in the fuel to prevent further wearing of the liner and piston.