So the present rad has the lower outlet hose connection on the passenger side? If so, then it is for the '70 and later engines and changing to the later, AL body pump would make things easier for your lower hose. Just look at where the timing marks are on the timing cover; if they are on the passenger side, then you won't be able to see them if you put the newer water pump on. To fix that, you can change the timing cover to a '70 or later or make a new tab, and then put a new TDC mark on the damper, or change dampers.