I ve been shopping for boats lately and have been running across ads with different mudbuddy motors such as the 4500 6000 and 7000. I assume as the biggest motor they make is 35 these different motors are all after the additions of mods but I m not sure what the horsepowers of these motors are after these mods. Can anyone help me out with what these numbers mean and what mods make these motors what they are.

The MB numbers indicate the model number. They do not dicate a certain horsepower but show an increase of horsepower over the base model.

4500, 5500 are the "black death" motors. They are the newer CDI motors wif built in rev limiters.
U also have the 45MAG, which is a beefed up motor wif stock carb.
Then u have the 5000, 6000, and 7000 motors are all stronger motors that have many mods and have different rev limiters up to like 5100 Rpms.
The motors are geared differently to get the most out of the engine without having to tack more tuan 5100 r so.

I have never seen any HP rating on any but the 45 MAG, which is said to be 45.