Bad rings, headgasket, cracked head, or stuck valve

 

Anything else I can try to help diagnos it before rippin her apart?

 

nothing other than repeat the test and hope you made some kind of mistake the first time.

with only 125k miles, your odds are good that you can pull the heads, find one cracked, replace one or both with new casting heads, and run it for a long long time.

 

Ya I checked it 4 times haha but I'm hoping its a head problem how much performance gain would I get with aluminum heads and a cam and a new intake manifold? And a sct ofcourse f this superchips I couldn't tell any difference

 

Well when's the build start? Sorry bud at least you know whats going on and what needs to be done. Go find a long-block that's your best bet. In my op aluminum heads have no place on a truck motor, You need to sit down and think about how you use your truck and then build the motor around that info.

 

merc, whats your opinion on the other cylinders at 130 psi? is that worth replacing heads only or do you think that's too low of compression and not worth putting money in unless you go ahead with rings and bearings.

 

Well I did the compression check cold instead of warmed up but the only hauling I every do is 3 dirt bikes (tight fit) but It is lifted 6 in and on 35s so a regear is needed but I'm looking for tourqe this 318 won't even do a burn out weakkkkk. I have to drive it wot all the time haha and I'm planning on a 408 in a couple months just buying a crate but I need something to drive now so maybe ill just polish this turd to get me by till then

 

If this was mine full rebuild, I would not just put a set of heads on "this particular" motor. As the op is thinking 408 I would find a JY motor and install it then rebuild his currant motor to 408.