83 84 250 into 430 motor

Hi I have a 83 430 cr with a spare 250 motor could anyone tell me if the cases and gearbox will swap across if I ever need to rebuild Thanks

There was no 1983 430CR as it was replaced with the 500CR for the 1983 model year. You likely have an 81 -82 430CR engine. If the 250 engine is 82 or later the gearbox is interchangable. The crankcases can be adapted for the 430 crank by removing the reduction web in the crankwell

Thanks for that jim sorry you are right its a 430 in a cr500 frame with a wr pipe , I will hang on to the parts for spares.