any body running a poly 318 in their car

IIRC in my Chrysler Engines 1922-1998 book, Willem Weertman says they reduced the weight of the LA by 25 lbs. compared to the poly/A engine.

The Poly is cool to me just because it's different and the combustion chamber design is more efficient than a wedge, meaning the fuel economy is better and it takes less mods to make more power (in theory). Like rumblefish said it's also an old-school thick wall design so the cylinders can be bored over a huge amount.

If you already have a car with one in it I'd say go for it, maybe get it running nice in that Coronet and find out how good it is then go from there.

One thing to note the later A-bodies are wider and can probably fit a poly easier than the early A-bodies the LA was originally designed for...