Mysql settings for query_cache_min_res_unit What is the best setting for query_cache_min_res_unit for these results:

+-------------------------+-----------+
| Variable_name           | Value     |
+-------------------------+-----------+
| Qcache_free_blocks      | 35327     |
| Qcache_free_memory      | 295242976 |
| Qcache_hits             | 236913188 |
| Qcache_inserts          | 49557287  |
| Qcache_lowmem_prunes    | 0         |
| Qcache_not_cached       | 7128902   |
| Qcache_queries_in_cache | 195659    |
| Qcache_total_blocks     | 426870    |
+-------------------------+-----------+


Do I need to change any other settings?

My website creates very large results. This is the current setting:

query_cache_min_res_unit = 4096


Info on the mysql dev website

If most of your queries have large results (check the Qcache_total_blocks and Qcache_queries_in_cache status variables), you can increase performance by increasing query_cache_min_res_unit. However, be careful to not make it too large (see the previous item).
Observations

Your question says you have 426870 for Qcache_total_blocks. Since each block is 1K, blocks are aligned to the nearest multiple of 1024. Thus, your query cache has about 417M.
If you divide Qcache_not_cached (7128902) by Qcache_inserts (49557287), this shows that about 14.4% (1 out of 7) of your queries could not be cached.
(Qcache_total_blocks (426870) - Qcache_free_blocks (35327)) / Qcache_queries_in_cache (195659) = 2K
On average, each query cache result hold about 2K, which is theoretically not possible. This could indicate some fragmentation in the query cache.

Recommendations

You need a bigger value for query_cache_size (perhaps 2G). If you are using InnoDB, you may get some performance increase if you disable the query cache altogether by setting query_cache_size to 0.
You need a smaller value for query_cache_min_res_unit (minimum value is 512 (0.5K)) if you want to hold small result sets.
You need a bigger value for query_cache_limit if you want to cap how big a result is too big.
See my earlier post : Is the overhead of frequent query cache invalidation ever worth it?