VD RF84 FC car in NZ

We have been running a VD84 over here for several years, but have always been plagued by over heating problems, the next fix will be a Alloy radiator, but is there anything else we should be looking at? we know that they were not a good car car design, but we have now got the handling sorted, it does what we ask of it apart from overheating, oh, engine is good we have had a couple of engines through it now, same problem, same engine build in other cars, no problems.

Roger