Could use some advice

Hey all, I need some help! We've been making good progress lately on our Kaiser but have ran into a few snags... as usually happen in this hobby:). After putting in the radiator for the first time on Sunday, I realized that I don't have the room I thought. Now I need a thin electric fan. There is about 3 and a half inches to play with and still have some wiggle room between the fan and pullies. But if needed I can still cut some sheet metal and gain about another inch or two.

Any suggestions on a good THIN fan?

Thanks

Jerome Zimmerman