Anyone got any idea how much coolant is needed to fill the system; I'm going to be changing, hoses, thermostat and water pump soon?

Here you go...



edit: You're unlikely to get all the old coolant out with just a drain & fill, so the above quantities will be ample.

You will only need a couple gallons of Dexcool.

Maybe take a look at my DIY that covers the whole job you are about to do with pics and parts list for 4.2L.

Any idea where the coolant drain plug is located?

Bottom corner on passenger side of radiator. After you get the plastics off the underside you will see it.

Is there a drain plug somewhere on the engine block?