Just bought a '95 Blazer and noticed the AF/coolant was brown. So, neglecting to read the manual, I flushed it and replaced with regular green coolant. No problems but the other day I'm going through the manual and noticed they recommend dexcool. So I talked to a mechanic friend of mine and he offered a doomsday scenario where I could mess up the engine. I immediately had it flushed and replaced with dexcool. Anyone know if the regular green coolant can do damage or was my friend engaging in hyperbole ?

Wow. There's alot of hype both ways on this. I've heard alot of stories of guys flushing the system completely and replacing with the traditional coolant with no problems. I've heard people say that it'll mix with the leftover dex-cool and cause more problems. I've seen no proof either way myself. The best thing I know is to make sure that the radiator cap is functioning properly, the system is kept full, and that no air is trapped. If you do that (along with periodic flushing) I'd say you'll be fine.

There is no problem with mixing both kinds together other than losing the long life factors of the Dex-Cool.
According to the GM shop manual for the 1995 Blazer, it should use ethylene glycol antifreeze. Personally, that's what I use because check how many problems have come about with Dex-Cool.

I would get rid of the factory radiator cap and replaced it with an aftermarket cap from Stant. It's a much better cap.