The stock radiator should be fine, if the system is clean and no blockage in the core.
I'm not familiar with Novas, If it has the stock pulleys and shroud (did Novas have shrouds?), that should be OK.
If the over heating occurs under acceleration (even slight) there maybe a timing issue. If the over heating occurs while cruising at RPM it could be running too lean.
Has this always been a problem?
LG
