Poly Engine what was good/bad about it and why is the LA better?

There was a dual-quad version, too; if I remember correctly...

Oh yeah, 57 and 58 Furies, which had a 256 duration cam and dual four barrels. 290 hp.

Also, there was an optional dealer-installed dual quad intake and hot cam for the 303 poly in 56 Furies, which gave it 270 hp - up from the standard Fury's 240. Standard Fury 303 had a single four barrel; same cam duration (around 240 degrees) as the 277 poly four barrel (200 hp), but with tighter lobe separation, which gave it a few more horsepower (as did the extra 26 cubes and higher compression ratio). Can't remember the duration of the optional Fury cam.