Unless you’re running a lot of memory (think more than 64gb) you won’t have any trouble below DDR5-6000, most Intel CPUs run up to DDR5-7000 just fine.
Make sure you’re running the latest BIOS version, they do improve compatibility and stability for fast memory from time to time.
i7-4790k is the highest drop-in replacement for the board after you do a bios update first.
That being said, it’s a pure waste of money. Don’t do it.
Also, to answer the question from the title: The highest Intel CPU that can pair with a GTX 660 Ti is the Intel Xeon Platinum 8480+. And on the mainstream-desktop it would be the Intel Core i9-14900K.