What are the factory specification for the coolant?

1989 would be the old style conventional green low silicate coolant made by whomever you like, Prestone, Zerex, Valvoline, Peak, Havoline and others. GM didn't start using Dexcool or any type of special coolants until 1996. Don't use the stuff that they sell that says "all makes and models" that is a modified HOAT coolant, and that engine will not like any of the acidic coolants like that. Also being this is an 89 you will want to change out any of the rubber parts of the fuel system if you have to run fuel that has alcohol added. The old lines are generally not alcohol resistant and tend to fail when used with it.

This is the Prestone that I have and there is not much information on it and it may not be the proper one. I think it is not good since it says compatible with all colors. What are your thoughts? See the pictures. What about NAPA conventional green coolant Part #NAF1GAL? I assume anything with a 1825M GM specification? AutoZone AZA003?

The NAPA will work fine.

I found the owners manual and it says coolant meeting GM specification 1825-M should be used which makes the NAPA a better choice than the Prestone by far. That Autozone brand I mentioned also meets that spec 1825-M possibly. Thanks for your help.

The GM spec is just telling you it is the old green coolant. Same stuff they used up until they introduced Dexcool in 1996. Pretty much every engine they made until then used the old silicate green coolant.