If my memory serves me correctly, there is a pic of this style manifold on multiple engines somewhere here on the site. I have been unable to find it despite my best efforts. I did find a picture out on the net. This is what it looks like;
The manifold is built from components; my guess would be to allow fitment to more engines w/o the effort and expense of building limited demand, engine-specific manifolds.
The beauty of the design is the uniformity of runner design from cylinder to cylinder, which speaks directly to the intake runner length issue you were looking to mitigate. A nice spinoff of the design is that it appears low enough to fit under a Cobra hood.
If you employed a Viper-style air box model and built two box-style air plenums over the air horns for each bank, sort of like a Viper uses, it would have a high under-hood wow factor — but it would not be exactly period correct. The bling factor, cool factor, and corrected runner metrics could possibly offset some of the period-correct angst ...
Another oh-by-the-way sort of issue that needs to be considered is that it would force you to EFI.