Will my drivetrain handle the horsepower?

I wouldn't go any higher than you are right now. Mainly because Nitrous is so hard on components. It's not like a normal engine that the hp comes up gradually. It slams right there. Unless your running forged pistons you might very well lay them on the track with a 175 shot before the trans. or rearend goes. Torque and traction are the trans. and rearend's worst enemy so if you don't hook real good the extra 75 shot probably won't affect them nearly as much as the engine. If your running sticky tires I bet it wouldn't last long at all at 175 shot. JMHO