From another post I made on the Hexagon manifold-
Re: Hexagon tool intake
The Hexagon was produced by them for the 1935 Miller/Ford Indy car and with that being a front wheel drive effort the engine blocks were reversed. Why Hexagon, or Miller, or Ford for that matter thought the carbs needed to be mounted conventionally is anybody's guess. Hexagon was a Detroit tool & die shop, possibly had history with Ford, and produced the patterns and machined the manifolds. The Hexagon was faster in qualifying, with Ted Horn being second fastest at 113MPH.
There was another manifold, a four carb, open plenum design (Miller?) that ran experimental Strombergs (some say Miller's) on most of the cars. It had a reversion problem with a fog of gas forming over the carbs and blowing back at the driver and riding mechanic. I'm no expert but I think reversion is caused by a "mismatch" in the intake tract length and RPM peak of the engine.
The Hexagon wasn't marketed for street use until the '40's and was popular for the backward facing carbs which afforded room for the generator in it's stock location.