Holley Air Horn Question

71GSSDemon said
Or just cut along side of the boss and grind smooth. Biggest concern is keeping everything clean or complete disassembly and then cut/mill/grind/clean and reassemble. I would also assume 3/4 of thread engagement on a 1/4" all thread is plenty. That is 3x the diameter = 15 threads. The wing nut has much less thread engagement.

I'll disassemble and clean, for sure.
When I cut the air horn off, there will be no threads, but that's addressed by cutting around the a/c stud boss.

TT5.9mag said
View attachment 1716153031
Close up, better pic. After you cut off the choke horn there is lots of smoothing that needs to happen. And you need to fill the slot for the choke linkage or unfiltered air will pass through.

I'll leave the bosses, stud and vent tube, thanks. I took the choke flap off long ago. I sealed the rod hole then.

TT5.9mag said
That’s ^^^^ funny.
I think the relationship between the air cleaner lid (especially with a drop base bottom) and the top of the choke horn and their proximity to each other, when installed and running in a car is where the big airflow differences will be seen.

This is why I want to remove the air horn. I don't know if it will improve air flow, but it can't hurt. I have 1" clearance between the lid and the front (higher part) of the air horn. I can't put a taller filter in it because I only have between 5/8" and 3/4" from the top of the air cleaner to the hood. It has a 3" tall element now.

RustyRatRod said
Yeah, I've said this before, but in the 60s, GM had a huge R&D program on airflow and air cleaner design. When their patent finally ran out on what they were making, Moroso picked up and ran with it. Those old 14" Moroso air cleaners don't just look cool, they straighten, smooth and direct airflow right into the carburetor. You can look at most an GM air cleaner from the late 60s pretty much until EFI and see the design.

It has an old gold Moroso on it. It doesn't look like the one TT5.9mag shows, though. I think it's from the 70's. It was on a friend's garage wall for years. It probably precedes the design of the nice one TT5.9mag shows?

My back's bugging me now. When I get this done, I'll follow up.
Thanks all!

Mine: