Holley vs. Eddy

I'll add my 2¢ worth here. IMO, the Eddy/Carter is better out of the box, but if you are able to tune it, the Holley will produce more power.

RE: Holley off friend's car. Though the temptation is to say that 323 isn't very far from 327 CID, it would be misleading to say that CID is all there is to it. Compression, combustion chamber characteristics, cfm on the heads, ignition setup, camshaft characteristics, and rear gearing all play a part in how well a carburetor will play when transplanted from one car to another. Will it work? Sure. But to get the optimal performance/economy balance, it will require some tuning.