Three years ago I was bolting together an LS swap and had nothing to put an air filter on. The MooSun 4-inch cold air intake kit was the quickest and cheapest way out, it went on in under half an hour, and I have bought about ten of them since — my own trucks, customer trucks, the same box every time. This MooSun cold air intake review is what that has actually been like: the parts that held up, the bracket I cut off, and the reason I would never sell one to somebody expecting horsepower.
As an Amazon Associate I earn from qualifying purchases. I bought this product myself and this is my own experience with it.
MooSun 4″ cold air intake review: the verdict
Bottom line first: this is a tube, a cone filter and a heat shield, and that is exactly as much as it needs to be. If you are dropping a 4.8, 5.3 or 6.0 into a 99-06 Silverado, or into a 1950s car that never had an airbox, this gets you running the same afternoon and it sounds right doing it. It is not a power mod, and it is not the filter I would run through desert dust. Would I pay full price again? Yes — same as the last nine times. check current price on Amazon
What held up
- Same filter on my own truck since 2023, rinsed with water, still pulling air
- Roughly ten kits bought, not one dead part back
- Under 30 minutes on a Silverado, cold, hand tools
- Aluminum tube and heat shield still straight after grinding a bracket off
What didn’t
- The supplied clamps are the weak spot — I keep spares in the toolbox
- One bracket would not clear, so it got cut off
- Any MAF truck throws a check engine light with this on it
- Generic oiled-cotton filter flows well and filters worse than paper
Why I bought it
An LS swap into a 1950s car leaves you with a problem nobody warns you about: no air filter. Carbureted cars had a round lid that screwed down onto the top of the carburetor, and an LS intake does not take one. So you either buy a filter and some couplers, or you fabricate the tube yourself.
When I want it to look nice I build a short custom one — a single tube, bent up and to the side — and put a good rewashable filter on the end. When I want the thing running tonight, I buy this MooSun kit. That is the whole decision.
What three years of using it has been like
The first one went on my own truck in December 2023 and it is still there. Same filter, same tube. I have rinsed the filter out with water more than once, let it dry, put it back, and the truck has not complained. Calling it rewashable is fair, but only just — it is a cheap filter and it behaves like one.
Since then I have bought about ten of these, mostly for customer trucks and mostly for stock-ish 4.8, 5.3 and 6.0 builds. Not one has come back to me. Piping, rubber and clamps are simple enough that there is not much to fail, and the failures I have seen were things I caused.
Sound is the real reason anybody wants this. On a stock truck with a stock exhaust you get an honest suction note when you get into it, and that is the honest gain. On my own cars it disappears completely — the engine and the mufflers are louder than the intake ever will be. I have never measured horsepower from one of these and I would not try. If your old filter was filthy you might pick up a little fuel mileage, and that is because your filter was filthy, not because the tube is magic.
It fits the 99-06 GM trucks the way the listing claims: 4.8, 5.3, 6.0, 1500 through 3500. On my own swap I had to trim a bracket before it sat where I wanted. After that everything lined up and I bolted the heat shield down and left it.
How the MooSun cold air intake install goes
On a truck it is a 30-minute job: pull the stock airbox, bolt the heat shield to the fender, clamp the tube to the throttle body, clamp the filter to the other end. Hand tools, no lift, no special sockets.
Bring a grinder if your truck is an oddball like mine. One bracket on my kit did not clear and I cut it off — five minutes, then it fit perfectly.
The clamps are the cheapest part of the kit. I have had them break, and I have watched people shear them by tightening past what they are rated for. Carry two spares in the truck and snug them; do not gorilla them.
If your truck has a MAF sensor in the factory intake, this kit will set a check engine light. Speed-density setups do not care.
What I’d change
Both things that annoyed me were small enough that I fixed them instead of complaining. The bracket I cut off, I cut off. The clamps, I replaced. That is the whole list.
If MooSun asked me: better clamps, and one more hole in the bracket. Everything else — the piping, the rubber fittings, the filter — is exactly what it needs to be at this level.
What the filter actually filters
The filter in this kit is generic oiled cotton with no name on it, so nobody is publishing a filtration number for it. The type, though, is well understood, and there is one genuinely good independent test of it: ISO 5011, run on a $285,000 dust rig at Testand in Rhode Island.
Paper captured 574 grams of test dust and passed 0.4 grams. The oiled-cotton filter captured 221 grams and passed 7.0 — and it loaded up and hit its restriction limit in 24 minutes where the paper filter ran 60. Oiled foam landed in between.
Read that as: an oiled filter flows better and lets roughly seventeen times more dust through by weight. On a street truck that is not enough dirt to hurt anything. In dust, it is exactly enough to hurt something.
Data: Arlen Spicer / Testand ISO 5011 comparison, reproduced by Project 200. The MooSun kit’s own filter is unbranded — treat it as a generic oiled-cotton unit.
Key specs
| Tube diameter | 4 inch (listing) |
| Fits engines | GM V8 4.8L / 5.3L / 6.0L (listing) |
| Fits vehicles | 99-06 Chevy/GMC Silverado 1500/2500/3500 (listing) |
| Finish | Black (listing) |
| What’s in the box | Tube, cone filter, heat shield, couplers, clamps, brackets (mine) |
| Filter | Reusable, water-washable, oiled (mine) |
Who should skip it
Skip it if you are not comfortable with hand tools — this is a kit you fit, not one that fits itself. Skip it if you drive in dust, live in the desert, or spend time on dirt roads, because an oiled-cotton filter is the wrong choice there, and I would say that about a much more expensive one too. Skip it if your truck still has a MAF and you are not planning a tune. And skip it if what you want is horsepower, because you will not get any.
FAQ
Does the MooSun intake need a tune?
Not on a speed-density setup — it bolts on and the truck runs. If your truck meters air with a MAF sensor, this kit throws a check engine light because the MAF is unhappy about the new tube, and you need a tune or a kit built with the MAF boss in it. I have not run one of these on a MAF truck long-term.
Can you wash the filter?
Yes, with water. I have rinsed mine out, let it dry and put it back, and it still works. It is a cheap filter, so I would not expect it to survive years of scrubbing the way a name-brand one does. Do not over-oil it when you put it back in, and keep a spare if the truck is a daily.
Will it add horsepower?
No. I have never seen a real gain from one of these on a mostly stock engine, and I have never measured one. What you get is sound. If your old filter was clogged up you might see a small mileage bump, but that is the old filter’s fault, not the tube’s.
Bottom line
If you are putting an LS into something that never had an airbox and you want it drivable this week, this is the kit I keep buying. If you want it to look custom, build a short tube yourself and put a good filter on it. current price and colors on Amazon