[elcamino]

Another thing I found in some GM TSB is that Dexcool is not back-wards compatible. Meaning if the vehicle never came with it, don't use it because it may react to the metals in the engine or the cooling system.

I know I have the TSB somewhere here but cannot find it right now. It listed what cars and truck came filled with it and those that did not and recommended against using it in those that did not.

So it would seem not the coolant to use in a classic car.