Air Filters.... HD RPO K47 vs. Standard

[KiloMikeZ71]

FWIU both filters will fit in the box just fine, the air boxes aren't actually any different.

FYI: With my 1997 K1500 with the 5.7l, the K47 HD filter does NOT fit in my standard filter box. I had read somewhere on here that one could get the A1301C filter and it would fit - even if not originally equipped - but it did not fit in my truck.

 

[df2x4]

FYI: With my 1997 K1500 with the 5.7l, the K47 HD filter does NOT fit in my standard filter box. I had read somewhere on here that one could get the A1301C filter and it would fit - even if not originally equipped - but it did not fit in my truck.

Are you sure it wasn't just an extremely tight fit? Which style of box do you have? There's two styles that the Vortec trucks got, a Donaldson and a Delphi. East302 posted pictures of each, first post on this page. The Donaldson is the top one.

https://www.gmt400.com/threads/air-intake.40309/page-6

 

[Supercharged111]

Aren't the boxes an early/late thing? Not a standard/HD thing.

 

[df2x4]

Aren't the boxes an early/late thing? Not a standard/HD thing.

Yup, far as I know anyway. I was just asking him out of curiosity.

 

[KiloMikeZ71]

Mine is the Donaldson. I worked pretty hard to get it to fit since I thought it should. But the box just wouldn’t close all the way so I couldn’t latch it. YMMV, I guess!

 

[454cid]

I like the Donaldson for the air gap, which would tend to isolate the filter from heat.... I don't like them for looking kinda bloated, and the wire latches are chintzy. Also, a mouse can really chew up the softer plastic of it wants to (dad's old 96)!

I do notice that the new standard filter isn't tight against the front wall of my Delphi filter box like the Fram synthetic washable filter had been. I did was that filter, and it's currently drying. I don't know if I'll use it again or not. I soaked it, and I think the foam may have been affected.

 

[df2x4]

Mine is the Donaldson. I worked pretty hard to get it to fit since I thought it should. But the box just wouldn’t close all the way so I couldn’t latch it. YMMV, I guess!

That's weird... Both of my '97s have the Donaldson boxes and they take the K47 (A1301C) filters just fine. It is a really snug fit, though. You have to kind of massage them into place sometimes.

Maybe the elbow piece that the filter slides onto wasn't seated in the bottom half of the box correctly when you tried shutting the lid? I've had that happen once or twice.

 

[Schurkey]

Just went out to my '97 K2500 7.4L. I suppose it may be different from small-block air filter housings.

I have the "Second Design" (smaller) Delphi air filter housing as shown in the link in Post 12 by df42x4.

My SPID tag shows "K47".

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And the filter housing is molded with both air filter part numbers.

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I bought the truck very used, so I won't promise that the air filter housing is original...but I have zero indication that it isn't.

I conclude that ordering "K47" on my vehicle gets you a bigger air filter, not a different air filter housing. But what do I know?



[Much-later edit] I tried crossing the number on the existing air filter to something recognizable, but had no luck. According to the Tape Measure, it's the equivalent to the A1300C, the smaller of the two possible filters.

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This air filter was what was in the truck when I bought it. I knocked the loose dirt and insects from it, and it'll go right back in.
[/Much-later edit]

 

[alpinecrick]

According to the info I listened to.....
The diesels went from the flat to the round filter because the round was higher capacity.

The K47 option does not flow air better than the standard, it just holds more dirt before becoming restricted.

And I don't trust that air filter indicator thingie on the Vortecs one iota......

 

[df2x4]

Just went out to my '97 K2500 7.4L. I suppose it may be different from small-block air filter housings.

I believe the 7.4L air boxes are a different part number, but very similar and take the same filters as you found out.