Speaking as someone who has destroyed both 885 & 955 motors, I can state with a fair amount of certainty here...
There is essentially nothing in common between T3-series motors & a G2 955 like the '04 Sprint.
If you're using a TBS as the base, find a green- or red-cam 885 motor, or even a 1200 four if you're willing to give up the triple character. The newer motors won't fit without about a good used bike's worth of parts & a whole lot of labor.
Cheers,
-Kit