My 273 turned out to be a 318...what did I buy?

I see someone's hot rod! LOL The fuel hose splitting the feed line to the carb bowls is one way to make it easier to swap jets at the track. So it has a Holley carb on it - probably a 4150/60, and explains why there's no bimetal choke in the intake. The intake someone will recognize.

A lot of it looks like it was fit in well. Wiring at minimum needs to be wrapped and supported. More later