I've been using tectaloy stuff in dads falcon, I don't recommend anyone using it unless they are willing to change and flush ya radiator every 6 months, it doesnt last long and gives little protection.
I'm not sure on everyone elses opinion but I am a very big fan of the astral coolant, it has everyting you'll ever want in a coolant in it, eg rust inhibitors, anti-boil/freeze and the biggest thing I like about it is lubricants. If you touch it there is an oily residue that stays on your hands. And after being in a car over 2 years it comes out exactly how it went in. I highly recommend it but it is very expensive, around $30 for 2L.
Alot of people also recommend toyota coolant, but from people at work who provide us with radiator flushing tools and equipment say its the worst they come across.
Phat Drift Damaged
Cobalt Blue 1994 EF XR8 5 spd
Fully optioned - Sunroof, cruise, body kit
Stock as a Rock for the moment