Truck running rough with p0307 code

[Backyard mechanic]

So I’ve been having problems with a pesky p0307 code and what goes with that code is arrive stabiltrac and check engine light flashes. My truck starts to idle rough and you can see it shake it’s running so rough. So I have change spark,wires, swapped cylinder 7 injector for 5,new ignition coil. I also ripped the head off and found cylinder 7 exhaust lifter was stuck shut so replaced it. I also sea foamed the cylinders and put it in the fuel tank and gave my engine a flush. I have 125 compression back in that cylinder and also have 58psi for furl pressure and still throwing the p0307 code and running rough. My next step is to change the intake manifold gasket n double check my rockers are tourqed right. Anyone else have any insight on this or have had to deal with this problem before. I also forgot I’m running a 2011 Chevy Silverado 5.3 with 250k on it

 

[zora]

How did you remove a head and not have to change the intake gasket?
What are the compression readings in the other cylinders?