[SCOTI]

A 235/75-15 is almost 29" tall so that is part of the issue (tall for a 4" front drop).

Bump-stops not helping limit travel is compounding the increased travel range making the inner wheel well the 'stop'.

Shocks w/too little dampening can be a contributing factor. Better mono-tube shocks can help depending on the current shock quality (age & quality).

If it has a coil cut from original springs, the spring rate can be too low for the drop amount + tire height combo. If you want to keep that tire height, you might need to step up to a higher rate drop spring which will help on compression.

Swapping a drum truck to stock discs widens the track width.
Drop spindles can slightly widen the track width vs. stock disc spindles.
Tires can make contact sooner depending on the actual final track width of the total package so the aftermarket wheel back-spacing is also a possible factor.