2 Strokes Down Under

can someone let me know if the front and rear cranks are the the same or totally different

They are different.
Front crank is longer on the left hand side so that the flywheel/stator can bolt up.

If you need new cranks, you can get some aftermarket ones for a pretty good price.
http://www.rz500performance.com/rzrd-500.html

He was talking to me about distributing parts for him in Australia, but it never came about. I'll have to get onto him again.

next question
can i just strip down a front and swap the ends over to make a rear
iam not racing just wanting to get an engine up and running for a reasonable price
cheers

Yes, you should be able to do that.
Do you have the gear to press them apart and back together?
Although if you're only doing the outer section it should be easy enough.

I rebuilt my cranks (including the web).. just needed to make up some pressing tools. Have to know how to get them balanced again too!

Does anyone make stroker cranks for the 500? Or a big bore kit?

The same guy rz50performance.com was working on strokers and big bores I believe. Not sure if he had one finished yet though.

Much easier to go for a big bore I would think, cast liners and all?

I've got a set of these cranks they are top notch!