one of my 4 diesel buggers is running a little hot. and it is the one with an aluminum head. naturally. 86 300sdl to be exact. have changed thermostats and the fan clutch. before i remove/replace radiator i decided to buy an ir point and read thermometer. a radio shack schmengie unit for $50 and change. question. in order to determine that my temp guage is correct and indeed i am running a little hotter in the 86 than the two 83s and the 84, where do i 'point' the thermometer? water pump assembly? top hose? bottom? thank you in advance. oh on the 'little' hot. seem to see 100 celcius on the highway. sometimes 100 + a little bit. the others do not approach this point. one clue to temperature sending unit problem is the the item in question comes up to temperature much more quickly than the other three. but then i be not sure of anything at this point. lastly, the 86 has 185k miles and by the looks of things the radiator seems not to be original.