7.4L Plugs Advice Needed

[Wellgeo03]

Well I cleaned and re gapped the plugs. They were all gapped quite wide, but not worn. Deposits were on all 8. Upon further inspection I may have found a very small vac. leak at the vacuum ball on the driver side fire wall. This may have been causing a slightly lean condition.

Upon further inspection I found that the air filter installed in the truck is 3.5" tall and should be 5.5" tall! So the truck has been running without an air filter for who know how long! There were some swear words when I found that! There was some dust on the inside of the air filter housing, so I am thinking this may have contributed to some of the deposits on the plugs.