gr8t73

I have a 73 with the stock copper/brass radiator and a ZZ4 crate engine with aluminum heads and was wondering what type of antifreeze should I use considering the aluminum heads.

REELAV8R

Nothing special just use distilled water to mix with.

I use standard green stuff (ethylene glycol) with aluminum heads and aluminum radiator.

F4Gary

This.

71 Vert LS1

Or in lieu of the distilled water you could use the pre-mixed green anti freeze. I keep both full strength and pre-mixed on hand depending what I'm doing.

If it's a fresh fire up of the engine I typically would put only water in case of a problem. Water is so much easier to clean up.

drwet

I agree. Use the green stuff. Prestone is my favorite brand but there are others that are good. Stay away from the long life red stuff. I only buy the concentrated stuff. Not that there is anything wrong with the premix, its just that you're paying a lot of money for water.

TimAT

And like 71 vert LS1, I fill with water for the first start on a fresh engine. If I have to dump it to fix a leak or what ever, It sort of cleans itself up.

zwede

I use 5-year universal Prestone. It's supposed to be nicer to aluminum than the old green stuff. I've used it for 20 years in my '71 (changing every 5 years) and never had any problems. Aluminum radiator is close to 20 years old and looks great inside.

gr8t73

I appreciate everyone's input. I think I'll go with ZWEDE's recommendation just to be on the safe side.