was your truck an original V8? [leading 'V' on the vin] if so, the rad may be mounted in the rearward position, and the aftermarket shroud won't work - and if so you should be able to get the fan within a 1/2" of the rad with a spacer and not need a shroud - otherwise you might have to make your own shroud ....
here's the plastic shroud [also next pic] I put on a '56 with a 350, positioned as HRL describes, it required a spacer on the fan shaft and was installed just by removing the fan first
Bill
