Intake grates do actually slow you down. Mainly by about 2 mph. Its extra drag in the water. They work great holding you down in rough water, thats it. An impeller will help in 1 area, not both or all of us would have that 1 prop. The best hook up prop is the Scat Swirl. Probably the best top speed prop is the Solas Concord.
As far as mods, first, filter and jet kit. Simple but effective. Next send the head out to get it modded. Still reliable, just more punch on it. After that, exhaust are expensive and require more in depth tuning. Reeds, not really worth it until you get into motor work. Its all in how deep you want to go. If you know how to listen to the motor and can hear it, you can tune easier and know when things are going to hit the fan.
