Foam or other pod filter suitable for a 3" velocity stack trumpet

I have been fiddling with various air filter/ stack arrangements for my 77, with TM/RS34 carbs. Both for looks, and hopefully to gain a little bit of hp as well.
My last setup is a pair of Mikuni velocity stacks, 70 mm long, and with a nice, large radius that gives a 3"/ 76 mm OD. In order to clamp a filter on to them, I have epoxied some rings cut from 75 mm OD drainpipe on to them, as you can see in the attached pics.
I also ordered a pair of UNI pod filters, with 3" neck, 3 3/4" OD and 4" long. Unfortunately, these are just around 2 1/2" / 63 mm inside. That means there is a lip that at least will cancel out any flow improvements from the velocity stacks. So now I am sort of stuck for options here, unless I build a custom box with UNI foam sheets,that is. I checked the Pipercross website, but no luck there either. Pretty sure K&N also will have some kind of feature that does not really fit with my stacks.
So now I wonder if anyone knows of pod filters with a 3" neck, max 4" length and 4 1/2" OD?

I made my stacks, I can't remember the uni number but they dropped on and don't block flow.

Might need to get ones with a bigger OD.

Trumpets look cool but from what I've read they don't work as intended with filters the velocity is slowed. And with out foam lots of air purity issues. Those UNI filters look trick but spoil the look somewhat. I have a set of trumpets but most likely I'll be running filters.

Even with the filter slowing the air, it gives a longer intake. That'll help low end a little bit, compared to having just a filter on the carb.