Originally Posted by MrTux
I just did some research and found out
mkfs.ext4 -b 4096 /dev/sdb2
Or if already formatted do
blockdev -setbsz 4096 /dev/sdb2
It's up to you of course whether you mark a thread as solved but I don't consider your original question solved at all (and I was intrigued to learn the answer ;-)).
Why? Well, firstly you asked about a block size of 4026, which I now assume was a mistake on your part. Secondly you asked for a solution using parted. The solution you have offered, using mkfs.ext4, is the obvious one and would have been suggested to you from the off if that is what you had asked.
By the way, the blockdev solution is not correct. From the notes in one version of man blockdev:
Note that the block size is specific to the current file descriptor opening the block device, so the change of block size only persists for as long as blockdev has the device open, and is lost once blockdev exits.
As far as I am aware, once your ext filesystem has been created, you can't change the size of the blocks, although you could certainly play around with block clusters (bigalloc) if you had a lot of large files and wanted to simulate the effects of a large block size.