Engine question please?

[McCoyAZ]

I am NOT a mechanic. Knowing that up front will help you answer my question.

I am looking for a 350 motor and trans to put in my 64 stepside C10.

There are tons of motors on Craigslist available but I am not savy enough to ask the right questions.

Someone please tell me in simple terms about new motor vs old motor and the complications involved with computers and such if I opt for a motor out of a late model wreck?

I want to keep it simple, make it a daily driver and have decent fuel economy.

I am also not adverse to the idea of a 283, 327 etc.

Thanks in advance.

Scott