I don't have a lot of history on this truck, because I just bought it. It has had a miss fire since I bought it. I thought I was getting the truck cheap and assumed the miss fire was a coil pack or injector ect. After the coil packs and injectors tested good, I checked for compression, and cyl. 3 did not have any. The rest of the cylinders had around 150 psi and cyl. 3 had 0. The gauge did not even twitch. Cylinder 3 was indeed the cyl. throwing a misfire code. I think the intake valve is hanging open, bent, burnt ect., because the #3 injector had carbon deposits on it. i have not done a pressure test or leak down test, but i was wondering if anyone has had these heads off. I was wanting to take the valve cover off today and inspect the valve train, but I'm not sure if there is enough room to remove the valve cover with the heater box or evaporator box or whatever its called, right up against it.
Can I take off the valve cover without lifting the body or removing the HVAC box?
Can I remove the head without lifting body ect.?
Is there anything else I should be looking for with the symptoms I described?

Note: Cylinder 3 has been repaired with a Time Sert, and the insert is not locked into the head properly it can and has came out with the spark plug.

I hate to put up these long posts when I first join a forum, but I hope you fine members can understand what I'm up against.