Can I interchange top and bottom mast pieces of Unifiber masts - for example, a 430 bottom with a 400 top?
The fast answer is - NO.
The reason is because of the integrated ferrule system we use, each top and base match a pre-defined conical shape determined by the optimum load distribution for that model.
In production the top is made to fit precisely on the base of the relevant model's base.
Different bend curves also have different wall thickness as well as varying geometric shapes, so it's technically not possible or advisable to exchange base and top parts.
We appreciate that it is convenient to have this and can see how many brands offer this as a cool option - and we also see the benefits to how changing tops and bottoms can make benefit sailing - it's just our method of providing both value and function makes it inadvisable.