I have a Win 7 computer with a SSD system disk and 2 data HDDs arranged in a Raid 0. I would like to do a clean install of Win 7 on the system disk. Will that have any impact on the Data HDDs or their Raid configuration? Or can I just install Win 7 and it will be able to see the drives as it does now?
No way of knowing... you didn't give any hardware/RAID controller details...
As you will be re-installing the drivers, Some RAID systems will recognise an existing array, some won't. Only safe way is to make sure ALL data is backed-up first, carefully read the RAID manual for whatever controller you have , and try it.