RM 250 engine swaps 5/19/2012 9:19 PM

Hey, just wondering if anyone knows if the engine out of an 84' rm 250 will swap with a 86' without much hassle. I got both engines and the bolt pattern looks alike but the engines are a different design, and since in 86' they decided to go with the blue and change the look. Both bikes are stuck in a gear though so would the parts match with one another?