Not 100% sure this is the right thread but didn't see a better option, if so just lmk and I'll move it. I have a 1984 K10 with a sbc 400 in it that I inherited relatively recently, been doing a bunch of work on it. I noticed the coolant in the radiator seems to be the normal yellow Prestone stuff, I was doing some research and people seem to disagree on whether or not it HAS TO BE dexcool or not so I wanted to hear you guys' thoughts. I know you definitely arent supposed to mix dexcool with any other coolant but it seems to be entirely just normal antifreeze. I drove it once before i took a look at the coolant and noticed it wasn't dexcool but it reached operating temperature fine and never overheated or had any other issues. Should I just leave it be or is it really worth flushing the whole system and replacing it with dexcool?