NAPA round style air filters for LBZ, LMMs can separate and start to 'unspiral' into the intake tube.

The specimin I removed today had set a MAF code, 35K miles on it, and looked like it was relatively clean.

I know it had been subjected to high volumes of air flow (i.e. almost constant towing) and plenty of rainy weather...the filter looked like the rain is what did it in.

OEM Delcos are all I plan to run from here on out.