New alum radiator arrived for my 68 Camaro with iron block 350. A rep for PEAK Antifreeze said yesterday, at Goodguys- Pleasanton, CA "only use their "Long Life 50/50" colored yellow with an alum radiator." He emphasized, "Do not use the green colored stuff. It is not for alum radiators." Should I get a refund on the Prestone green-colored antifreeze I just bought and get the yellow antifreeze? The green coolant container doesn't say do :confused:not use in alum radiators. What's best?

If that yellow stuff is kin to GM's Dex-cool DO NOT use it in a car that is not equipped with an overflow tank that will keep your radiator completely full of water. Dex-cool (and similar brands) and air do not mix. They will form a brown sludge that will plug your heater core and radiator tubes over time. Use whatever the radiator manufacturer recommends, not what some anti freeze guy is trying to sell you.

Terry, I just bought a Ron Davis aluminum radiator and asked them the same question about which antifreeze to use. They said the green is fine as long as you use distilled water.
There's been alot of discussion here about DexCool and it sounds like it needs to used in a closed loop system like the newer cars have. Not the ones that are open to atmosphere like the 1st gens are.
I personnelly ran the Zerex G-05 in my aluminum radiator, aluminum head engine going by the reccommendations here on this site. (I believe this is a yellow color too). This was before talking to a Ron Davis rep.

Motorcycles all have aluminum radiators (at least the Many I have owned). I have always used Peak regular anitfreeze in a 50/50 mix with distilled water. No corrosion and no problems (in 10 years). I am diligent in flushing the system once a year.