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

[454cid]

For some reason, I always thought my truck had the HD filter originally. However, I just pulled out the original filter, just for the fun of it. I keep it in a bag in a K&N box. I used to install it while letting the K&N dry after cleaning. The K&N is long gone. I've had a synthetic washable Fram for years.... which has been discontinued, for years.

I have the A1300C which is the standard air cleaner. Checking my RPO list, I do not have K47 which would be the HD filter. I really have no idea why I assumed I had the HD filter.

Anyone have the standard and HD filter side by side? I assume the HD filter is just bigger around?

I actually have a new standard duty filter on the way..... it'll be my 4th filter in almost 300K miles. The original, the K&N, and the current Fram. I guess I change them every 100K miles on average

 

[Supercharged111]

I've been floated that option at the parts store. Our trucks stock filters are terribly shrouded by the box itself. I can't imagine anything inside there outflowing anything else that goes inside there. I like to cheat and bang my filters on the ground to be a cheapass and squeeze more life out of them.

 

[df2x4]

I assume the HD filter is just bigger around?

I believe this is correct, although I've never had a standard filter on hand to compare directly. Both of my '97s have the K47 RPO, so both have always run the ACDelco A1301C.

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

EDIT - This info is concerning gas trucks, I believe on diesels the K47 RPO included an entirely different air box.

 

[454cid]

I've been floated that option at the parts store. Our trucks stock filters are terribly shrouded by the box itself. I can't imagine anything inside there outflowing anything else that goes inside there. I like to cheat and bang my filters on the ground to be a cheapass and squeeze more life out of them.

By shrouded, you're talking about the air having to travel around the space in the inside to find all the surface area of the filter element? I think the HD filter is supposed to be for dusty situations, so more instantaneous flow was probably not as much a design concern as much as maintaining a given flow for longer.

For me, either I don't recognize a dirty filter, or I don't encounter much dirt while driving. It stays clean forever. I think I've only washed the Fram once, and it's been there a long time.

 

[Supercharged111]

By shrouded, you're talking about the air having to travel around the space in the inside to find all the surface area of the filter element? I think the HD filter is supposed to be for dusty situations, so more instantaneous flow was probably not as much a design concern as much as maintaining a given flow for longer.

For me, either I don't recognize a dirty filter, or I don't encounter much dirt while driving. It stays clean forever. I think I've only washed the Fram once, and it's been there a long time.

Logging MAP will tell you if a dirty filter is actually a restricted filter. Of course I've never logged MAP for that particular purpose.

 

[454cid]

I believe this is correct, although I've never had a standard filter on hand to compare directly. Both of my '97s have the K47 RPO, so both have always run the ACDelco A1301C.

Any idea what triggers the K47 RPO?

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

EDIT - This info is concerning gas trucks, I believe on diesels the K47 RPO included an entirely different air box.

I think the diesel, at least some years, uses a flat filter. I've wondered about swapping one in. I've never seen one up close and have no idea if it would be an easy bolt in, or not.

 

[df2x4]

Any idea what triggers the K47 RPO?

No idea, sorry. Like I said both of my '97s have it, one is a K1500 Suburban with the 5.7 and the other is a C1500 with the 4.3. So it seems that engine size makes no difference.

 

[Supercharged111]

Any idea what triggers the K47 RPO?



I think the diesel, at least some years, uses a flat filter. I've wondered about swapping one in. I've never seen one up close and have no idea if it would be an easy bolt in, or not.

It totally did. I too can't say what years because I barely ever see them in the junkyard.

 

[454cid]

It totally did. I too can't say what years because I barely ever see them in the junkyard.

Looks like 96/97 was the split, and the diesel k47 looks like it uses our gas element... the flat filter is their standard.

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[395detroit]

It totally did. I too can't say what years because I barely ever see them in the junkyard.

92-95 6.5 diesels had the flat filter. I don't know about older 6.2s, I would assume though that from 88-95 all GM diesels would have used the flat filters. It would be a complete waste of time to put a flat filter on anything because they don't seal easily around the bottom edge.