First off GM antifreeze is not compatible with regular antifreeze.
You can tell the difference in the color. GM antifreeze is reddish were regular antifreeze is greenish in color.
Standard Prestone antifreeze will not interchange with Gm's Dexrol antifreeze.
When you buy antifreeze if you don't GM antifreeze you have to make sure what you are buying is labeled as being compatible with GM antifreeze.