'66 deville engine rebuild?

i have a '66 sedan deville with the 429. my friend said it needed the engine rebuilt so he let me have it cheap. my question is should i have the engine rebuilt or does anyone know where i can get 1 already rebuilt and just drop it in? what would be cheaper? any help would be appreciated!

What is wrong with the engine that it needs to be rebuilt? There are rebuilt 429's available. Most rebuilders do sell rebuilt ones. Or you could take your engine somewhere and have them rebuilt it. Check with Jasper Engines or some of the other rebuilders.