As long as you dont mind losing your historical data, this will be MUCH easier for you than trying to upgrade your way all the way to version 8.
I have opened version 3.5(x) scripts in the 8.02 editor without any issue converting them, but it wouldnt hurt to have maybe a version 7 editor around just in case. I dont think you will need it.
Make sure you take a look in the scripts for any references to documents outside of the repository. It was somewhat common practice (although incorecct) to store XML documents in C:\XML or similar paths rather than using the repository.