Hi,
Did you install the source for php 4.0.4 as well when you installed your system? If so, then I assume the source will be under /usr/src or something like that.
I'd recommend you install the latest version of PHP from scratch by downloading and compiling it.
Download it from php.net and follow the instructions in the INSTALL file.... trust me, it's very easy :-)
once you download and unpack the latest distribution, do this:
./configure --help
look for any options related to your interest; oracle 8i.
If you aren't compiling with apache, then make sure you choose the right apache compilation options. again: this is covered under the INSTALL file included with the distribution.
-sridhar