Taking the LS swap plunge/need to sell/trade Poncho 400 w/muncie

[av8or32]

Well here goes. I'm seriously considering doing this to my 69 Firebird. First things first. I'm looking at either a late model GTO powertrain 5.7 or 6.0 6spd or a late model Camaro/Firebird same deal. How difficult/costly is this swap really? How much should I expect to pay for the powertrain and lastly, I need to sell my current engine/trans in my bird. It's an origional (not to the car) 69 400/Muncie 4 spd combo. It's running great but I really want to get into more modern power/gas mileage etc.