What do you guys recommend for removal. PB Blaster? Heat? Impact? No sure were to start.

 

Have you just tried to loosen them first? Did you bend back the little lock tab? I would use a penetrate first, let it soak for 15 min and then try to wrench them off.
With aluminum heads the bolts should not be rusted to the heads.

 

As I recall you will need to use a 12 sided socket (they are a 12 sided bolt and the 6 sided socket does not fit tight), forget what the exact size is maybe 13mm as I recall. Spray them down with PB Blaster and start your truck so they get hot and use a breaker bar. Just go SLOW at first as you do not want to break them off.

 

This man knows his stuff! I would add to clean the threads wit a wire brush and soak them with pb blaster.Then when you break them loose slowly work them back and forth as you loosen them.

 

Also forgot if they are rusty then they are going to get stuck in your socket and you are going to have fun getting them out. What I had to do is stick the socket in a vise and tap the bolt out with a punch and hammer every single time, fun stuff.

 

The correct socket is a 12 point -12mm. When I did my headgasket job at 120k the manifold bolts came out much easier than I thought they would.

 

ditto to all above......and I would add that you should probably use new bolts when putting everything back together. Voice of experience here.....I broke one of the old bolts without hardly any torque on it and stripped the threads in the head on one other. Get some grade 8 bolts, new gaskets, you'll be fine. FYI.......bolt thread size is 3/8-16 NC, and the added bonus.....with new bolts you can install "hex" headed ones thus eliminating the pesky 12 point issue next time. Good luck.