
I found a couple air filters off GM trucks that are a lot larger than ours and fit on 4bbl qjet & others.
The 2.25" small one is off our trucks up to 72. Notice how small the inlet hole is also.
Next 3.25" is off a 73+ GM truck. The inlet is also much bigger.
The last one is 5.25". I found one of these big ones in the back of a late 70s-early 80s truck in wrecking yard...no engine, so I am not sure of the application, but it was $5. Then I found another at a swap meet with a K&N filter all for $10. Still don't know exactly what they came on, but see, they are almost free, when you find them. My 79 454 dually only came with the medium sized one, but It is getting the bigger one!
I put the medium sized one off my 454 on a 402 I am driving.