It is safer, cheaper, and more worth your time to sell the $ and purchase the 6. by the time you locate the motor, transmission, front suspension (the V6 weights more so you have to change springs and other front end parts) brakes, engine harness, radiator, intake, throttle hook ups, and all the other little parts, you could have bought yourself the V6, and saved yourself time and money. Even if you had all the parts you needed for the project, you’re still looking at least 1 to 2 weeks before you would be able to drive it. If you have a shop do it for you, it's going to cost you way more then what the vehicle is even worth. Also the other consideration to look at, many cities have laws that restrict the changing of the engine size. If the vehicle is registered with a 4 cylinder and you have changed it to a V6, the State can and often will deny you registration on the car. I have seen it happen. It's best to just sell the 4 and purchase the V6.