Im going to use castrol magnatec 10w-40 in my CA, i think penrite make a 10w-50 which would be good if your going to do alot of hard driving as it has that extra 10 if the motor does get a bit hot and for summer months
Gearbox wise im gunna use nulon smooth shift 75w-90 in my stumpy , generally most nissan gearboxes will take this weight of gear oil