I tested all cylinders three times at five cranks (first three numbers) and one time at six cranks(last number).

Starting at Driver front as one and pass rear as eight
1 330-320-320-340
2 300-300-300-320
3 300-290-280-280
4 210-210-200-215
5 340-340-340-360
6 260-260-260-270
7 180-180-180-180
8 120-120-120-120

 

Hummm....

#1 is fine
#2 is ok
#3 is pretty low
#4 is a dead hole
#5 is good
#6 is pretty low
#7 is a dead hole
#8 is a dead hole...

You sure you did not have any leaks in your compression gauge? No issues with your injectors being removed or oil in the coolant?

How many miles on the truck?

This could be a valve issue, could be a ring issue.

Anything lower then 320 or so is not good, it will run fine at 300 if there all pretty even, but will smoke more and have lots of blow by.

340 up is good with a new motor being around 400psi.

 

New compression gauge, injectors are still in, don't think there is oil in the coolant. About 250K Lots of blow by so I figured it needs rings. Need to check push rods to make sure they are all straight. Guess I should pull injectors to see if o rings are bad. It smoked a lot and used about 1.5 gal of oil in 7500 miles. Thanks for the input

 

If it ran thru 1.5 gallons then its time to pull it.

Heads or rings, its going to need work.