Originally Posted by Mr Hyde
The main thing to look for is a coolant that is borate and silcate free. Most long life coolants typically are, but if it doesnt say so on the bottle, skip it. Any coolant that has borates & silicates can do a number on your water pump, so avoid them at all costs.
I guess most of you miss this post from above. Silicate is not good for aluminum. It will react with aluminium and causes corrosion. Silicate can also gel up and clog your cooling system.
A lot of new engine block and head are made of aluminum now a day.
Just do a search on "silicate free coolant".