Distributor Springs for Recurve on U

Changing the springs and changing the number of degrees it advances by cutting or lightening the weights, or modifying their travel on the shaft,is about all you can do to change the advance curve.

Automobile 'advance recurve kits' used to just include an assortment of springs. (along with some way to change the vacum advance, which your U distribuitor does not have).

There isn't a lot you can do. Have you modified the engine at all or why do you want to change the ignition curve?

If you need some springs and if automobile springs would work I would give you some leftover ones from a recurve kit. Not sure if they would work but I thought I would help if at all possible.