I noticed i had a random popping out of my tailpipe on my 87 d150. It turns out that #2 plug is gas fouling. I did a compression test and it has 120 lbs.,not real high but it is a 1989 TBI engine. Can my carb be the culprit as the ignition system is good and the plug wires are good.

I don't see how a the stock carb on the stock intake could only fowl one cylinder. I;d triple check the ignition system, especially the plug.

What Supercuda said.

750 street demon with an edelbrock performer intake. Replaced the plug.

I would check that spark plug wire carefully (I would test all of them while your at it ) with a Volt Ohm meter and twist both ends, spark plug and distributor ends, to see if it is going bad (varying ohm readings)
I've had several wires go bad at the 90 degree distributor ends, the nylon that is graphite coated had all the graphite burnt off of them
I cut around one inch off of each one of the bad ones to get back to some good looking inner conductor and race that car some more
IHTHs

I'd expect a miss if the plug wire was bad. Back in the day, a popping at the tailpipe was interpreted as an exhaust valve problem; but without knowing if that same cylinder is lower compression, or higher leakdown, or how well the wires test, or a number of other things, I wouldn't say that's definitely the problem.

I'd start with a bad plug, a bad plug wire, or a bad terminal in the cap. I've seen old wires short to ground where they lay against other stuff. If the spark can't get to the plug, it will gas foul it.

If it had port injection, I would also be looking at that injector, but a carb/throttle body would usually gas foul all the plugs, or all the plugs on the same intake plane. Gene

Thank you all for your help on this. I’m gonna start with the small stuff first like a new set of wires. The engine is a month old so i don’t foresee a valve issue but ,who knows?

Open up the left side air mixture screw and see if it helps. I had the same problem years ago. It was air mixture screw turned in too far.

Is it possible that the shiney is oil fouling (oil ring did not seat).

You can smell the difference between oil and gas fouling

Only if you know how
I know there is a bunch of different stuff on trouble shooting cars and other problems I don't know
OP, if the plug is shiny it has oil on it, if it is not shiny and really black cover up with guk it may be gasoline
You could swap that plug into a cylinder that is looking good and see if it will clean up in that cylinder and see if the other plug goes bad

If it's gasoline or oil fouled it's wet and you can smell the difference. It's it's dry and powdery it's running rich, if it's hard and shiny it's burning oil. If it's white it's coolant.

Used
Actron Kal Equip Spark Analyzer 2969 units
are now pretty cheap.

https://www.ebay.com/itm/Kal-Equip-Spark...5.m43663.l10137

When they dropped below $50
I bought a second one
so I could easily compare the:

Peak KV
Burn KV
Burn time in milliseconds

On the wires to plugs on two different cylinders.

These simple to use little meters help track down ignition gremlins

Oscilloscope units that would display traces from all eight cylinders at once
Would be better
But they are bulky and much more expensive.

Exhaust valve. Pulling the head and sending it to the machine shop that built it.