or you are interested in Oracle 9i's
DB_nK_CACHE_SIZE
n can be 2,4,8,16,32?

If this is the case, here is an example (assuming your db_block_size
is not 16K):

alter system set db_16k_cache_size=8M
create tablespace test_tbs blocksize 16K;

You can then create segments on test_tbs.

Two reason I think of it:
1: different tablespaces/tables use different block size (DSS and OLTP hybrid)
2: transportable TBS