QNAP Failed Backplane, Moving data to new NAS

[Enquiries]

I have a QNAP TS-251 with two WD Red 4TB drives, which recently experienced a failed backplane. I believe the drives are both good, but the RAID is degraded as a result of the backplane. I purchased a new QNAP TS-464 and 2 new 8TB Seagate Ironwolf drives. I'm wondering what would be the best approach to migrating my existing data.
I hope to continue to use all 4 drives, but won't installing the old drives in the new NAS require a reformatting in order to set up the new Storage Pool?

[ed]

When you move old drives to a new nas you will be given a choice to format or keep everything as it was on old nas.
if there is no choice like that, contact Qnap.