I use a VW caddy Rad in the racecar, it works well, but there is some fabrication involved, in other words it doesnt just fit, u need to make it fit.
My advice is to take the OEM one in for refurb at silverton, will be slightly more expensive, but way less hassles to refit, PS u dont get brand new giulietta rads anymore, but there are plenty second hand ones, If u dont succeed I have 2 spare rads(dont know condition so will still advise a pressure test)