The belt settings will be in the box with the new belts. They usually come in a set of two belts (an injector pump drive belt and a camshaft drive belt) and new pulleys. Will be about £60 for the belt kit.
That's not considered to be a "safe" engine so without doubt you will have a lot of damage. Sometimes as well to get an engine from breakers and fit new belts to it before fitting to your car.