http://androidforums.com/cdma-evo-3d-all-things-root/648902-radios-hboot-firmware-all-downloads.html
Much easier and quicker to change hboots than to ruu. Ruu unroots the phone and changes everything to stock.
Meaning you have to add recovery again and root. Plus the ruu takes awhile to download and about 10. Minutes to run.
If you want all the firmware from the ruu, you can use the download in post 3. Though for the evo v you would be getting the old radio since there have been updates since.
Basically I would just change the hboot. You can use the sprint 1.58 hboot if you need the newest.
Edit: i guess it depends on what you are doing. You want to return completely to stock? Or you just need the stock rom?
If you want to keep root, change hboots and flash the rooted stock rom. If you want the phone completely stock use the ruu and then take the OTA updates.