Offroad-Express

I'm looking to buy an 80 Landcruiser, anything I need to look for in particular, faults common to this model, rust etc..
Is their much difference between the 12 & 24 valve motor to justify paying the xtra for the 24?

Thanks

the 12 valve ones all did crank bearings at 100km but its unlikely there would be many around that havent had them replaced by now, its a common problem for the chassis to crack badly around the steering box, thats all I know about 80's