John,

I wouldn't use an 'automotive' antifreeze, primarily for the silicon levels of those products. You'll get the dropout that Jon mentions in an earlier post if you use those products. While you're at a HD parts facility pick up a few test strips to check/test the Ph of your antifreeze. Be sure that your coolant is within the prescribed Detroit Diesel specs. You can buy pint containers of SCA to bring the levels up to snuff and then keep them at that level with the additive included in your replacement filter.

Remember that 50% of all engine failures are directly related to cooling system problems.