TOG - the shroud you picture is a good repro of the factory original for the 60's cars and trucks - I found one from a car at a wrecking yard, as seen
here on my '58, and added a spacer behind the fan to get it in the 'sweet spot' right at the opening of the shroud ... the fan has to be less than an inch from the rad in order to cool properly without a shroud
Bill
