Is this for a 66 Cuda? If so, and you are running the original radiator, you will be looking for the 2 piece metal shroud and special smaller 17" fan. The hot ticket for that setup is the 6 bladed fan with a clutch from a later car and eliminate the spacer. That's what I'm running in my 66!!
If you need a 17" 6 bladed fan, let me know, I have a couple extra!! Ill also include a pic of my setup when I'm at the big computer!! Geof