This Swap IS NOT as difficult as you may think. I got an RB25DET in Stock by the way if your looking for one. My 89' Skyline has an RB25DET, and I can just tell you, it's an awesome motor, 250 hp. I have helped do 1 RB25DET into 240 swap here, and as far as I can remember, we did not run into any major difficulties. Good Luck.