The factory installed Torque To Yield head BOLTS
and not studs. A world of difference.
You should find better friends if one told you to use the stock bolts...
or better yet, kick him instead of yourself
Like Evil Eye said, If you are lucky, it is just the degas bottle cap. Don't count on that being the case, it sounds more severe than that.
Go buy a scangauge2. It runs 165 bucks at your local auto parts store. It can monitor your Engine Oil Temp and your Engine Coolant Temp easily and without too much of a bite to the wallet. It is actually an excellent tool given the low cost considering all it can monitor, but that is a different discussion for another time. Get it on there, now. Have that friend of yours take you for the ride. Leave the truck where it is and only drive it if you absolutely must, to minimize the chances for more damage.
Then drive the truck (easy now) up to full operating temp (ECT should be about 190°F give or take a few degrees). Go out on the highway and set the cruise control for 60MPH. When you have been driving on flat ground for a good 10-15 minutes, check the temperature differential. Should you see oil temps more than 15°, drive home, take the degas cap off (CAREFULLY and when cooled off) and start ordering parts for the oil cooler swap/egr delete. Reason to remove the degas bottle cap? The cooling system will be under pressure and, if you left it on, that pressure could force coolant out of the failed egr cooler and into the passenger side exhaust manifold.
If you get enough coolant down in there, and into whatever cylinder has an exhaust valve open, you could hydrolock the engine. Hydrolocking it isn't a given, but it does happen and you can easily avoid it by simply doing it.
Excessive puking could very well mean that your head gaskets are gone again. So if you do all of this work yourself, and find that it still pukes, your looking at doing the head gaskets all over again.
If you want to delete your EGR, delete it
with a kit.
Like I said before, check out that link and read up on what is suggested for parts and what are mandatory for parts.
Doing this job as a newbie under the hood can take you a full 10-12 hour day, maybe longer. It just depends on your skill set.