Except for the manufacturer block (block 0), all other blocks on MIFARE Classic cards can be written (after proper authentication and unless they have been permanently write-protected by setting the sector's access bits).
So for a MIFARE Classic 1k card, blocks 1 to 63 can typically be written (with the above mentioned exceptions). You can find the datasheet with the complete memory layout and explanation of access bits here.
Similarly for a MIFARE Classic 4k card, blocks 1 to 255 can typically be written (with the above mentioned exceptions). You can find the datasheet with the complete memory layout and explanation of access bits here.