Been searching for awhile. There has to be a thread on this...
Getting close to starting the 400 stroker up for the first time in 20 years...researching everything.
At this point I'm leaning toward just plain green 50/50 antifreeze. Seems to be a bunch of internet suggestions in many different directions.

I came across Valvoline max Life antifreeze (its yellow) but that seems to be commercial. Not in any store-would have to order/ship it...

This motor is all new inside and out. I guess technically the whole car is new inside and out at this point!

I use 100% Preston antifreeze. No water dilution.
Max cooling and corrosion.
You will the high end stuff has no
Water added

Always use distilled water, not exceptions!

http://articles.orlandosentinel.com..._antifreeze-coolant-ethylene-glycol-pure

There is the Evans stuff. You run that straight. And you can’t mix that with existing coolant so a fresh motor, heater core, and radiator is the time for that.

Evanscoolant.com

Otherwise, the green stuff 50/50 is fine. I use tap water because I’m too cheap and lazy to buy distilled water

Anti freeze is one of those more isn't better things. Buy some prestone or other brand name and mix it 50/50 with distilled water. Will cool better than 100% antifreeze and have all the corrosion inhibitors available.
Antifreeze mixed 50/50 cools better than 100% . Just the way it says on the bottle, can ,container, vessel.

Here's an interesting article I found on antifreeze when I was chasing down what to put in my Challenger.

http://www.engine-performance-onlin...ifreeze/engine-coolant-antifreeze-types/

Yea I found a similar article though that ones much more detailed. I guess Ill have to decide soon. I bet very few people know how many differences there are in antifreeze.
Most of the containers aren't easy to tell which particular type they are.

I looked at MSDS doc for the Evans antifreeze and I could not find
any specific compound(s) unique to any other antifreeze.
The difference I found was the requirement to NOT add
water to antifreeze.

We really should describing as “coolant” and not antifreeze. You need to cool the engine in hot climates or cold. But only need antifreeze in cold climates.

Pontiac’s run hot. Typically if everything is working well there should be plenty cooling capacity with 50/50. I’d rather have more cooling capacity and
no corrosion.

I STAND CORRECTED. Checked out Prestone site
you must have some water mixed with or does
not work properly. 50/50 or 70/30

Yup, hard to figure out which is what.
I managed to find on the back of the yellow Prestone bottle, in very small letters near the bottom, that it is Organic Acid Technology (OAT.)

The Evans site claims that is has a much higher boiling point than ethylene glycol. This makes it more effective since it won’t boil at the hot spots and will cool those locations better. If true, that’s an advantage. Also, without water, no corrosion .

For info, the corrosion inhibitors in prestone are themselves corrosive but cause the cast iron and steel surfaces to passivate which protects it. Stainless steel passivates in air. (I took a graduate level corrosion course)