Ah sorry, thought my car would be in my signature. I'm driving a 1992 Hilux Surf 2.4TD. They have notoriously inadequate cooling systems. It only overheats slightly when i'm carrying a big load up long steep hills. I've checked all I can in the cooling system and have a few mods planned to help with the cooling.
I'm also planning to fit some ball joint spacers and a body lift to give me about 4" more room for some bigger tires (which won't help fuel consumption either!)
Anyway, thanks for the advice, looks like steel are the way to go alright.