Increasing row size beyond 8k

There was some talk a while back of changing the blocksize to 32k in
order to increase possible row size, I need to do this (and don't want to
screw anything up) but am unsure about how to go about it.. Is BLKSZ (if
that's even correct) simply a PG variable somewhere?

I see this in my LINT kernel configuration file (I'm using FreeBSD 4.0)

# BLKDEV_IOSIZE sets the default block size used in user block
# device I/O. Note that this value will be overriden by the label
# when specifying a block device from a label with a non-0
# partition blocksize. The default is PAGE_SIZE.
#
options BLKDEV_IOSIZE=8192

That sounds like what I'm looking for and since it's set to 8k, looks like
what I'm looking for -- so would I be correct in changing this value and
re-compiling my kernel?

Thanks!!!

-Mitch