I've never sat a CA into a B110. But something I found when I fitted an L20B into a KB310 was the height of the drag link was more of an obsticle to getting the engine low. I sectioned the guts out of the the Xmember to get the tall L20B block down lower in the hole. BUt then the engine sat on the drag link. (It was much worse at full lock too)
So we spend most of a day raising the floor of the (810) sump to get more clearance. (ONly to later discover that the rack an pinion 910 L20B sumps came with the very shape we strived so long and hard to create)
Since CA's came from R&P equipped cars already, It's safe to assume they have this shape too. (To be honest, I've never actually looked closely at the CA sump yet)
A mate of mine who is putting a CA18det into his 2door sedan has done the same thing. Sectioned the center part of his Xmember, and altered the sump to clear the drag link. So as to get the motor as low as poss.
BUT, when the 1st sump was modified, the engine was out pof some early EXA type car. The very early CA twin cam engines had different ports, and no girdle. When he shelved the idea of the supercharger, and bought a complete det engine instead he found that the sump in the pic above hit the girdle. (When We did my L20B sump, we used blue tack to check the crank to sump clearance at bdc)
So While I have nothing really to offer here, thats my thoughts on low low you can go.
Although, NickM tells me that the drag link from a B210 has a different shape to it. And allows a whisker more low-ness.