Even if the 289 (supposedly) bolts straight in, the engine will be too far forward and the weight distribution will increased at the front of the car. If you are going to do this conversion and want the car to be a good handler then do it right the first time. The JTR manual should be your bible.
Dont listen to people that think they know, do what I did and buy the manual , stay close to this forum and you cant go wrong.