Fan spacer size?

Jim,

You have to go by what your car needs. The fan should overlap the shroud by about 50%. This means that half of the depth of the fan should be inside the shroud, and half outside. This will help ensure that the fan pulls the air through the radiator better.

Put your parts together and find out how much shim you need to get your fan to be half in and half out of the shroud that you are running.