need help deciding on a new motor for my car

[Gongshow]

I might need a new engine for my car, its a 1966 impala, currently has a 283 in it. At the end of last summer my current engine was blowing white smoke like crazy. I am just waiting to pull it and go over it. In the meantime I am looking for possible replacements, just in case.

My two choices are a brand new crate 350 290hp or a 1970's rebuilt 327 that our mechanic at work owns that he claims is pushing just over 400 hp. the 327 is about $600 more than the new crate engine. my logical self says 'buy the new one', but my male ego says '400+ hp!'

What are your thoughts?