Nice project!
The length of all inlet runners (from trumpet/air stack to valve) must be equal. Otherwise it won't be synchronized at some certian RPM and thus you'd get lower power.
The max torque RPMs comes from cam durations. You can degree a cam, to see an actual duration @0.050 in (for example) and simulate it in some software to see what intake/exhaust lengths work best.
Usually people underestimate the importance of good length tuning: exhaust header design and length, and intake manifold design and length. It can add more power than some decent cams.
Again, in terms of reliabilty for endurance racing, it should be dry sump.
And the oil cooler should be as big as possible. Because the oil may seem to be okay, but it's much hotter on the con-rod bearings than it is in the pan. Plus an oil filter should have no relief valve, so there would be nothing to break and low restriction.
Also a "crank scraper" plate could be good.
As for carbs, if they didn't come in the same set, or have been rebuild previously separately, there is a way to balance them among three.
The floats (F) must be equal in weight among three carbs.
This ensures equal fuel delivery to all 6 ports. Your ones look pretty new though.
Just my 2 cents.