Trying to replace intake manifold

Well Hi. I'm stuck in a situation with my 90' S10 Blazer. I'm just trying to save a buck or two. Saturday my temp gauge shot up past 280* and I pulled over at gas station. I discovered that coolant was leaking out. The leak is located (looking directly at the engine) on the left side almost behind the alternator. I'm not sure if the intake manifold (on top) is directly connected to the heads? If you were to look at the engine with coolant added it leaks on the front left side on the intake manifold like a stream so obviously theres no gasket left. The gap is about 1/2 to 1 inch. Now where can I get a more detailed diagram for the engine ro should I just consider doing a complete overhaul considering there is 270k miles?

I have 277k on my k5 blazer. With that type of coolant leak, its probably a headgasket. Check the oil, if it comes out milky, it is a headgasket. Yes the manifold is directly connected to the heads. Thats how air gets in. I dunno bout complete overhaul, its not too hard, no cam sensors or anything. Good luck. Check a haynes manual.