IT's an easy enough equation. You want to measure from the innermost side of the radiator to the mount on the water pump. Now deduct one inch. That's the maximum you can go including both fan, clutch and spacer. Manufacturers and shops should list the dimensions for most of the products online.
As for the fan diameter, you'll need someone to measure and provide you with the diameter of the fan shroud's primary opening at its NARROWEST POINT. The fan shroud is a two piece unit and you should get the measurement with the second lower piece installed. Again deduct one inch and that would be the maximum fan diameter I would use... I might be inclined to go just a little smaller yet.
All in all not too difficult of a project, just need the one measurement from the shroud which you don't yet have and you should be good to go.
__________________
If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum.
If you're so inclined I'm always more than happy to accept tips via PayPal. 
Tip Jar ---> 
|