What do you guys make of this?

[Chopperman]

Maybe 1,000 miles on these plugs. Running some fuel additive, but whats weird is that the colored plugs are only from the PS side head. Very weird. Truck burns a quart of oil every 3 tanks of gas, but no smoke.

Thoughts?

[cep62]

Well I'm no expert , but seeing as no one else chimed in I'll offer some of my little knowledge .
First answer some questions.
How does the truck run? , why did you pull the plugs after 1000 miles.?
have you had any work done lately ?

Because it is on one side of the engine ," Maybe" a lean condition caused by a leaking intake gasket ,
or " Maybe" deposits from a coolant leak , again bad intake or head gasket ?
Have you ever done a compression test?

[Chopperman]

Truck developed a slight miss, so decided to pull plugs to read em. Doesn't over heat or leak water, 120-140PSI in all cylinders. Checked for air leaks via brake clean while running and found none. Other than the truck being a little low on the power side, it runs fine. I rebuilt the carb a few weeks ago and it was running great.

I'm thinking a jet got plugged or something on the DS side port. Going to pull it apart and check it out.

[Manny]

My read on those is the drivers bank looks to be a little lean. The third to the right on the passenger side bank to me is about perfect. Light brown staining is where you want to be that one is pretty good. What motor is this age etc?? Still say your not terrible but your lean driver side and the front two on the passenger side are a little fat. Also stock intake 2 bbl 4 bbl??

[Chopperman]

tried rebuilding the carb again. It was a no go. Threw down for a new holley 350, trucks is like a new animal. I now have power I never new existed!!!

[Ranchero50]

What intake? Most intake manifolds feed two middle ports from one venturi and two outside from the other. I'd be more apt to look for an exhaust blockage on the rich side or in intake fitment issue.