The "shroud" for a puller can simply be a sheet of flat aluminum with the sides folded down to stand off from the radiator a minimum 1/2", folded again on the sides to form a flat flange to bolt to the radiator (flat Z on the sides) and a large hole on the surface for the fan. Run the largest SPAL that fits your radiator width. A SPAL programmable controller is a plus, fed by a SPAL sender in the intake water jacket port.