Oil in Coolant

A leak-down test will help determine if its the head gasket. If the LD test is ok then it could be the intake.

Try a spritzer bottle with soap water and have someone keep the car running and spray the solution around the heads and intake..................it is hard because the symptoms sound like a hg.......

I would put my hard-earned money on that lower intake gasket, here's why:

1) Coolant in oil---leaks past the intake gasket into the lifter valley, to the oil pan.
2) "Smoke" out of tailpipes---white "smoke"=steam=coolant in combustion chamber. Coolant pulled into intake tract/combustion chamber via vacuum.
3) Doesn't idle---vacuum leak from atmosphere.

All those, plus you mentioned that you had just monkeyed around with it. As was mentioned in above posts, use some substance to spray along the length of the "lower" gasket. (I'd use carb cleaner or even WD-40, not soap and water.) Chances are good that the engine will rev a little when the affected area is reached.

Outside of an intake gasket, I would say that maybe the intake manifold is cracked. That is not likely though, as it was apparently running fine before. Let us know the result.

A long shot here I know but ..............

When you put the lower back on

Did you run the bolts enough times to obtain even torque

Sometimes ... it takes 5, 6 or even 7 times to get even tightness
and then
After a couple of heat cycles ... you need to run em again
cause
You WILL find a few that need a bit more of a twist

Again ... just a shot in the dark

Grady

I have to say I am with reddy351. Sounds like it is your lower intake manifold gasket.