Air Filter Housing for 0-7448 conversion

Danny Phillips

Danny Phillips

Member
Hey Jeff, I got the carb installed today and I was trying to install the offset air filter and noticed 2 things. The z rod that goes into the carburetor is 5/16-18 and the carb is 1/4-20. Is it acceptable to tap the carb to 5/16-18 and if so will that void the warranty. Also on the top front of the fuel bowl is a plug? That sticks up higher than the air filter that would require denting in the air filter. Other than those 2 items carb went on great. Thanks to you and michael. Danny
 
I have never seen a 5/16" offset air cleaner stud! And all Holley "street" carbs built in the last 20+ years have had a 1/4"x20 air cleaner stud hole.

The oem Holley 2300 which was used on the ihc vehicles that had the large oil bath air cleaner were 5/16" due to the weight of those air cleaners when loaded with oil. The air cleaner studs for those carbs however had a 5/16" thread for the carb end with a "step-down" to 1/4" for air cleaner top retainer. In some cases a tall "adapter" was used that was 5/16" into the carb with another 1/4" hole drilled/tapped for the stud.

I just got home from a parts run, I have a source that has the 1/4" offset studs hanging on the wall now, I should have bought some for stock here, you can bet I will pick some up when I'm next in town on Thursday!

Two things to do right now so you can mount the air cleaner...make a temporary "offset" stud out of a piece of easily bent 1/4" allthread from the hardware store. I'd recommend not drilling/tapping the stud hole any larger. Over time, I have to install a helicoil in that hole if the air cleaner stud is r&r'd over and over.

When I install the stud, I use a jam nut on it after adjusting the length. And I install it with loctite red before snugging up the jam nut.

That air cleaner must also be a "drop" base if it hits the fuel needle valve lock screw and adjusting nut on the top of the float bowl. Proper workaround for that would be a 3/8" "spacer" made for that purpose, those today are normally a delrin-type plastic.

"drop"-type air cleaner bases whether offset or not, don't work in the IH application because of this exact issue and the fact the base will hit the water neck if a 14" air cleaner is used. That is in regards to the Holley 2300 carb on the 2v intake. The Holley four barrel version (or the edelbrock) mount the carb a bit further to the rear so there is not an interference issue on those even though in some cases the air cleaner base actually touches the Scout II water neck if it's the oem 90* style. One of the earlier water neck used with non-air pump motors is a workaround for this problem, but you also have to run a "spliced" top radiator hose for one of those necks (but not the other).

If you can hold out for about a week, I'll send you the proper stud and a riser/spacer for the air cleaner. I can't make a run to town until Thursday, then I'll mail the stuff Friday and you should see it a week from today.

Sorry for the trouble, we'll make it right!
 
Thanks michael. The stud that comes in the k&n off set filter is definatley 5/16-18. I did buy the filter that Jeff sells for this application and I didn't want to dent in the lower part because the filter won't fit properly. The spacer won't be so high that it hits the hood will it? Any way I won't be going anywhere for a week or so. Thanks for your reply michael. Danny
 
Danny phillips said:
thanks michael. The stud that comes in the k&n off set filter is definatley 5/16-18. I did buy the filter that Jeff sells for this application and I didn't want to dent in the lower part because the filter won't fit properly. The spacer won't be so high that it hits the hood will it? Any way I won't be going anywhere for a week or so. Thanks for your reply michael. Danny
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Some of the efi throttle bodies used in late-model domestic stuff requires the use of the 5/16" offset stud/air filter base for adapting the typical aftermarket open element air filters.

As to what your actual hood clearance is on a Scout II without a body lift, use a ball of play dough on top of the air cleaner you have now and slam the hood. Then measure the thickness of the stuff to determine available clearance. I keep a couple of cans of that stuff here on the carb bench, Jeff's kidz gave it to me several years ago when they were here! Works really well because it won't stick to anything!
 
I'll try the playdough trick michael. I still have the problem with the interference with the needle valve cover screw. I'm wondering if I would be better off with using a 10" or even a 7" air filter. I can play with spacers and see if I can get it to fit right. Thanks michael.
 
Danny phillips said:
I'll try the playdough trick michael. I still have the problem with the interference with the needle valve cover screw. I'm wondering if I would be better off with using a 10" or even a 7" air filter. I can play with spacers and see if I can get it to fit right. Thanks michael.
Click to expand...

That's odd that you are having clearance issues with this air filter. I have sold this setup many times before and no one has brought up to me about any clearance issues with the carb. Next time I have one of these 2300 carbs in stock I will certainly check for clearance issues as the last thing we want to do here is sell you parts that don't work together.
 
A 10" x 2" air cleaner will clear everything just fine, I normally use those up here but some folks simply don't like the "look"!

In actuality, I think what happened is a "packaging" problem (not at the ihon end!). When the components of that particular air cleaner were packaged together at the manufacturer, there was either a mis-label or the entire assembly was packaged under the wrong part number.

The 5/16" stud is the real clue, this item is most likely a dedicated assembly for an efi throttle body.

I have used only one 14" cps air cleaner with the offset/drop base onna Scout II with this same carb and it cleared everything nicely. But in the cps line, there are two different "drops" for the bases, the deepest one will not work on any IH application, those are used on chev apps.

My suggestion at this point..."do over"!
 
Thanks michael. There were no labels on the air filter box at all. According to the pictures I've seen it isn't a drop but I'll get with Jeff tomorrow and see about returning it. I haven't been able to find a 3/8 inch spacer, that looks about like what I need to clear the needle valve cover.
 
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