i used to belong to a forum for toyota hilux surfs, the forum is full of stories of overheating issues and cracked cylinder heads, I had the over heating problem myself on my 1994 3 litre diesel auto I tried everything but it still overheated when towing, so I sold it for 4000nzd, paid 2500nzd for a 1996 300 TDI, and am really pleased with it the best thing being cheap parts from paddocks etc.
Toyota quoted me 1500 nzd for an alternator 4000 for a radiator....750 nzd for a viscous fan, the head was only 1500nzd though, mainly cos everyone was buying chinese ones.....which were better than toyotas..basically the surf waas under cooled which is pretty bad when selling them into aussie etc
having said that the local landrover dealership quoted me 120nzd for track rod ends and i got them from paddocks for 10% of that......