Hi there, anyway what happen in your motor? try to check out with ebay. I believe there were some motors posted last week that are quite cheap just be sure to have a competent installer for less head ache.
A conversion from a 650 or 700 to a 1000cc prowler can be done, just ask 1PhatCat. Unfortunately it is quite extensive and much easier and cheaper to just sell ur 659 and buy a 1000. The setups are completely different, 650 clutches are on drivers side of engine, 1000 clutches are on passengers side. Plus the diff's rotate opposite from a 650 to 1000. I could be wrong but if you want info I'd search and ask 1PhatCat. Good luck.
you have to swap the differentials as well. that creates the most problems. they are opposite drive. It is this way because the h1 prowler motors are backwards. the 1000 if facing forward. We almost did one but my buddy ended up finding a cheap 1000 to build.
I think you will be money ahead if you repair your 650 and sell it. Then find a 1000. If you do the swap, you will be left with an oddball machine with many custom made parts that you will find hard to sell later on. In addition to the differences others have mentioned, the suspension set up on the 1000 is better as well.