Engine overheating/Head Gasket questions

So I have been given a 98 Olds Intrigue with a 3.8 that burns coolant, has oil in the coolant, no coolant in the oil, when you turn the car on with the radiator cap off it bubbles out of the radiator mouth. The upper intake (plastic one) is not cracked or melted from what I can see. Also the lower intake seems to be fine, though I am suspicious of the lower intake gasket (the one between the block and heads and the lower intake) as it fell apart a little when I pulled the lower intake. I have pulled the front head and its head gasket looks fine. I am just regrouping before I take on the task of pulling the rear headers to get to the rear head studs.

So my questions are first and foremost do I have to pull the headers to get to the rear head studs or have you guys gotten wrenches in there to the rear head studs with the headers on or what? Whats the best way to do this? Also, should I be pretty confident that the rear head gasket is the issue? I assume since the coolant system was pressurized it must be the head gasket, especially since it had oil in it. Where should I look on the lower manifold for a crack? Any other advice on this would be great. I know these iron heads and blocks aren't prone to head gaskets failing but this engine has about 190k on it. One more thing, the guy before me who had this used some stop leak in the coolant and it seemed to fix the problem for a little bit. Thanks for the input!

So I figured out the best way to do it is to use a winch and pull the back of the engine forwards, rotating on the transaxle. So I got the heads off, looks like I was wrong about the head gasket because they are both fine. So I am thinking it much be a crack in the head or the block. It wasn't the EGR valve stove pipe melting the upper intake, or the upper intake gasket. And like I said the coolant was bubbling and had some oil in it, so I'm thinking a crack is between an oil and water jacket.
I had gotten the car from a friend, and his daughter drove it and had over heated it a few times. From the water pump and from the upper intake failing on 2 different occasions. So it makes sense that after the 2nd overheating a head or the block cracked.
Any way that I can check the block jackets for a crack, maybe by pressurizing a water jacket and sealing all the other water jackets and seeing if oil gets pushed up through an oil jacket? Any advice at all would be very appreciated! Thanks!

One more thing, do people plate the EGR valve on these? I think it would remedy the hot stove pipe issue if it wouldn't throw the computer badly. I had a 3.0 mitsubishi engine in a dodge stratus and plating the EGR valve was common.

have the heads checked for cracks/distortion. overheating one time will damage the heads.

the intake egr damage is indeed a 100% failure when over 100,000mi.

replace it.

look at the plugs removed and the head combustion side for coolant residue.

since you had coolant with exhaust pressure it should reveal its path.

Thanks cat. I think the pressurized coolant could have been from the oil pressure in a potentially cracked head.

So I found out both of the heads were cracked. I am going to the junk yard to get some new heads. And yes I know its not ideal to just throw some old heads on there, but this car is a beater and I just want some better MPGs than the 5.9L dodge I am driving around right now. Will any heads from the 3.8 series 2 work as far as mounts, alternator brackets and such go?

So I found out both of the heads were cracked. I am going to the junk yard to get some new heads. And yes I know its not ideal to just throw some old heads on there, but this car is a beater and I just want some better MPGs than the 5.9L dodge I am driving around right now. Will any heads from the 3.8 series 2 work as far as mounts, alternator brackets and such go?

when you call the scrap yard tell them what you need exactly. they will know for sure what parts you need and if they have them.

used heads are ok . just have the machine shop check them out. get reciept from scrap yard . if defective bring back.

use a machine shop that aren't crooks.