I have an 82 Cb900f that i got running after it sat for 15 years. Got it running and everything works no major leaks but it burns oil on start up and under throttle. I’ve been told that it could be a number of things from timing being off to rebuild the entire engine. One issue on my motor is the front cam timing chain adjustment bolt is stripped and i would need to fix it or replace the head if i rebuild it. I now have the opportunity to buy an 81 Cb900f engine not burning oil and was dyno tested with 20k miles. Would this be an exact swap lining up and are there any differences internally like valve sizes or timing or anything? Thanks for any information.