Does the MX5 fan draw air in from the top? That seems less than ideal for all sorts of reasons. Maybe this could be a better choice. (I have seen Chevrolet S10 ones mentioned too) Looks very neat and has its own squirrel cage. The fan really needs to match the size of the original can but that could be adapted, or the original fan swapped over.
https://www.ebay.co.uk/itm/Chevrolet...8AAOSwnDxUdGxf