An air filter box from a 97 to 2000 year models, K47 I believe is what they are called, will maybe eliminate that grainey stuff from getting into the engine.
It also uses a different air filter that has a very positive seal on it.
Dont even go with one of those K&N filters. I threw away the one that was on My truck as soon as I opened the airbox and discovered what was in there. Those things are plugged up before adding that oil to them. I can not imagine anyone running such a contraption. Just more snake oil.
I grew up using oiled air filters including K&N. Here in the desert you learn fast from everyone fighting the fine dust offroad. A lot of places here have “POOF SAND” because when your tires hit it, no matter the speed it literally makes the sound and instantly becomes a cloud of fine dust.
In the fleet (back in the 90’s) we did testing of different filters. So a couple of the guys and I used the equipment and did our own for offroading. We learned if you oil exactly the amount K&N recommends, it doesn’t filter as good as the best paper filters do the first few hundred miles. But if you use 10% or more oil, then it filters better than the paper ones right from the beginning. You do need to wash and redo the filter sooner than the paper filter would get replaced by about 10%. Using a filter sock over it helps a lot on extending the time between cleaning, didn’t help run cleaner but also helped keep water out.
I have ran a K&N on my hummer since 04ish. I ran oil samples using AC Delco, then K&N with 10%, 25%, 50% and 100% over oiling. All tests showed the K&N ran as clean as the Delco. But over 50% extra oil really caused restriction sooner. Mind you this was the old paper media. The newer paper media filters improved their dirt amount caught and the filter life. If I didn’t already own the K&N I would just run AC Delco and be done with it.
But keep in mind, I learned proper oiling on dirt bikes before Van Halen became Van Hagar. I didn’t look at money saving of not buying new air filters, I went by where my personal results were from in the past. I have 70,000ish miles on the optimizer which only ever had the K&N. If not for the glowplug that damaged the piston, I would not have torn mine all apart. The rings and cylinder walls show no signs of damage from fines. I really could get away with not using the ball hone even for new cross hatching. I tried taking pic with my phone to post, but each pic shows different reflections that aren’t really there. Later I can dig out the old rings and do a close up - convex will show better than concave I think. I will also try using wife’s better phone camera then.
K&N did outperform other filters pre 2000 for sure, probably up to 2005. In 2020- probably not. Definitely not the newest AC Delco. They did force the big boys to redesign and improve their stuff, and I always appreciate better products to choose from. Sometimes $ comes first and sometimes it’s quality.
I may not actually need to replace those other 4 injectors, but I will replace all the return lines since there is some very slight fuel seepage coming from one behind the turbo.
