Install 392 (Gen 1)Hemi

It isn't cheap at all but it's been made pretty easy since it's become so common. The 392 is the same as the 5.7 for the most part, so just look to see what the 5.7 guys are using. There are headers, mounts, etc for the setup.

What are you planning on doing for an engine management system? Do you have the stock stuff or are you going aftermarket?

There are adapters to put 727s and 833s behind a gen 3 hemi.

It's all a pretty common swap these days and that 392 won't be any easier or harder than a 345 or 370.