I love my Pentax 67ii and Manfrotto 410 geared head but it doesn't let me tilt when I shoot vertical.
I don't think there's L bracket for 67ii in production. Even if there is, is it possible to use it with the 410 head? Is there any other option instead of going ball head?
There was an "L" plate from Kirk, you might find one used. There was also an adapter, also from Kirk I believe, the allowed the use of Arca/Kirk quick release plates on the 410 head.
After that, an L-bracket will get you what you want to accomplish. There are "universal" L-brackets, if Kirk or Really Right Stuff (and others) don't have one purposefully for the 67II.
I have the L plate from Kirk on one of my 67II's, it works okay. It's not as rigid as I'd like it to be. That was one thing I never liked about the 410 head, that I never had much confidence in it being solid enough for the 67II's with long lenses.
I have the Hejnar kit for my 410, and to rotate the camera 90 degrees I then use an RRS CRD rail in the Hejnar clamp and clamp the camera plate to the CRD rail. Balances better than tilting the head 90 degrees.