ok checked the headers, and both sides seem to still have the metal pieces but i dont think they were spot welded at all.
Did you check to see whether the welds were OK? Just try lifting the metal pieces and if one side turns out to have a cracked weld, bend the metal piece away so it can't rattle.
Someone also mentioned the exhaust shroud hot air pickup thingy as a source of rattles. This should be around the primary exhaust pipes on the passenger side, unless it has been removed or has rusted away. If it hasn't been removed, remove it. You don't need it in Australia!
haha just the kind of answer i was looking for! i was going to take the airbox off and put something straight over the carbs and clamp it on..
This may make your car a bit slower but it will have a very loud induction roar!
also i seem to have miss calculated my operating temp figures, it sits around 55-65C to be more accurate, i guessing its a little cooler because of the larger copper based radiator that was replaced for the old one.
55-65 is too cold.
The middle of the temperature gauge is 80 degrees Celsius and that's roughly what your car should operate at, regardless of the size of the radiator. 33s take a while to warm up compared to modern cars though.
The cooling system thermostat blocks the flow of coolant so it can't get to the radiator until the engine is properly warm, meaning the radiator doesn't do any cooling until the thermostat says so. If the thermostat is stuck open, coolant will constantly be going through the radiator and the engine won't get warm until you're stuck in traffic for ages. The faster you go in this situation, the colder your motor will get.
You may be getting confused with the radiator fan switch, which turns the electric fan on when the coolant in the radiator is too hot (insufficient natural airflow to cool it down).
Edit: This is my 666