Which Coolant to use in a new L31, and which intake gasket?

[clinebarger]

Originally Posted by derotoreut

Heard nothing but bad about Dex Cool. Don't have any experience with it though. Never heard any bad about the old green. I used standard Prestone in my 5.3L swap.

Dexcool is an outstanding coolant when used properly & actually lasts longer than 5 years/150,000 miles.....It's more of a 10 year/300,000 mile coolant in the right applications.

The main corrosion/rust inhibitor is 2-EHA (which stands for 2-ethylhexanoic acid) & has 3 drawbacks......

*If ran low & cast iron gets exposed....It will quickly rust & the rust will migrate to the heat exchangers (Radiator & Heater Core), Not an issue with all aluminum mills & unlikely to happen on Aluminum Headed mills. Maintaining proper level is very important!!!

*2-EHA is known to be a Plasticizer (Softens Plastic) & did no favors to the Plastic Frame gaskets used on Vortec 350's.

*The Organic Acids don't play well with Soldered Copper/Brass heat exchangers, Not that I believe the Acid eats away at the Solder, But removes the Silicates that was plugging the tiny pinholes that were already there.

Air exposure in a remote coolant recovery reservoir in itself does nothing to Dexcool!
Mixing incompatible coolants & off course....Running the level low enough to expose cast iron is when you see the "Death Cool" build-up.