I am planning on having a 18 x 8 airboat built after hunting season is over, so I am currently gathering price information for the loan. I need to figure out what size engine I will need to push the boat loaded with 7 men and gear. I need the boat to run across dry ground with just me and gear. It is going to be a heavy high sided boat with decking back to the driver seat and 1/2" poly on the bottom. I am leaning towards a Chevy LS, LX, etc type engine, but I don't know what size or HP I should put on the boat. I don't want to be under powered, but I don't want to blow extra money unnecessarily on an over kill. I thought about the levitator, but it only produces 450hp, and I don't know if that will be enough hp to do what I want it to do. I have one shot at this and I don't want to make a mistake or regret my choice. I would really appreciate your suggestions.